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RUDEUS, a machine learning classification system to study DNA-Binding proteins

DNA-binding proteins are essential in different biological processes, including DNA replication, transcription, packaging, and chromatin remodelling. Exploring their characteristics and functions has become relevant in diverse scientific domains. Computational biology and bioinformatics have assisted in studying DNA-binding proteins, complementing traditional molecular biology methods. While recent advances in machine learning have enabled the integration of predictive systems with bioinformatic approaches, there still needs to be generalizable pipelines for identifying unknown proteins as DNA-binding and assessing the specific type of DNA strand they recognize. In this work, we introduce RUDEUS, a Python library featuring hierarchical classification models designed to identify DNA-binding proteins and assess the specific interaction type, whether single-stranded or double-stranded. RUDEUS has a versatile pipeline capable of training predictive models, synergizing protein language models with supervised learning algorithms, and integrating Bayesian optimization strategies. The trained models have high performance, achieving a precision rate of 95% for DNA-binding identification and 89% for discerning between single-stranded and doublestranded interactions. RUDEUS includes an exploration tool for evaluating unknown protein sequences, annotating them as DNA-binding, and determining the type of DNA strand they recognize. Moreover, a structural bioinformatic pipeline has been integrated into RUDEUS for validating the identified DNA strand through DNA-protein molecular docking. These comprehensive strategies and straightforward implementation demonstrate comparable performance to high-end models and enhance usability for integration into protein engineering pipelines.

bioinformatics↗

The sum of two halves may be different from the whole. Effects of splitting sequencing samples across lanes.

The advances in high throughput sequencing (HTS) enabled the characterisation of biological processes at an unprecedented level of detail; the majority of hypotheses in molecular biology rely on analyses of HTS data. However, achieving increased robustness and reproducibility of results remains one of the main challenges. Although variability in results may be introduced at various stages, e.g. alignment, summarisation or detection of differences in expression, one source of variability was systematically omitted: the sequencing design which propagates through analyses and may introduce an additional layer of technical variation. We illustrate qualitative and quantitative differences arising from splitting samples across lanes, on bulk and single-cell sequencing. For bulk mRNAseq data, we focus on differential expression and enrichment analyses; for bulk ChIPseq data, we investigate the effect on peak calling, and peaks properties. At single-cell level, we concentrate on identifying cell subpopulations. We rely on markers used for assigning cell identities; both smartSeq and 10x data are presented. The observed reduction in the number of unique sequenced fragments reduces the level of detail on which the different prediction approaches depend. Further, the sequencing stochasticity adds in a weighting bias corroborated with variable sequencing depths and (yet unexplained) sequencing bias.

bioinformatics↗

Mid-infrared photoacoustic brain imaging enabled by cascaded gas-filled hollow-core fiber lasers

SignificanceExtending the photoacoustic microscopy (PAM) into the mid-infrared (MIR) molecular fingerprint region constitutes a promising route towards label-free imaging of biological molecular structures. Realizing this objective requires a high-energy nano-second MIR laser source. However, existing MIR laser technologies are limited to either low pulse energy or free-space structure which is sensitive to environmental conditions. Fiber lasers are promising technologies for PAM for their potential of offering both high pulse energy and robust performance against environmental conditions. However, MIR high energy fiber laser has not yet been used for PAM because it is still at the infant research stage. AimWe aim to employ the emerging gas-filled anti-resonant hollow-core fiber (ARHCF) laser technology for MIR-PAM for the purpose of imaging myelin-rich regions in a mouse brain. ApproachThis laser source is developed with a [~]2.75 J high-pulse-energy nano-second laser at 3.4 m, targeting the main absorption band of myelin sheaths, the primary chemical component of axons in the central nervous system. The laser mechanism relies on two-orders gas-induced vibrational stimulated Raman scattering (SRS) for nonlinear wavelength conversion, starting from a 1060 nm pump laser to 1409 nm through the 1st order Stokes generation in the nitrogen-filled 1st stage ARHCF, then, from 1409 nm to 3.4 m through the 2nd stage hydrogen-filled ARHCF. ResultsThe developed Raman laser was used for the first time for transmission-mode MIR-PAM of mouse brain regions containing rich myelin structures. ConclusionsThis work pioneers the potential use of high-energy and nano-second gas-filled ARHCF laser source to MIR-PAM, with a first attempt to report this kind of fiber laser source for PAM of lipid-rich myelin regions in a mouse brain. The proposed ARHCF laser technology is also expected to generate high-energy pulses at the ultraviolet (UV) region, which can significantly improve the lateral resolution of the PAM.

neuroscience↗

Unifying concepts of biological function from molecules to ecosystems.

The concept of function arises at all levels of biological study and is often loosely and variously defined, especially within ecology. This has led to ambiguity, obscuring the common structure that unites levels of biological organisation, from molecules to ecosystems. Here we build on already successful ideas from molecular biology and complexity theory to create a precise definition of biological function which spans scales of biological organisation and can be quantified in the unifying currency of biomass, enabling comparisons of functional effectiveness (irrespective of the specific function) across the field of ecology. We give precise definitions of ecological and ecosystem function that bring clarity and precision to studies of biodiversity-ecosystem function relationships and questions of ecological redundancy. To illustrate the new concepts and their unifying power, we construct a simple community-level model with nutrient cycling and animal-plant mutualism, emphasising the importance of its network structure in determining overall functioning. This type of network structure is that of an autocatalytic set of functional relationships, which also appears at biochemical, cellular and organism levels of organisation, creating a nested hierarchy. This enables a common and unifying concept of function to apply from molecular interaction networks up to the global ecosystem.

ecology↗

Selection and evaluation of qPCR reference genes for expression analysis in the tiny egg parasitoid wasp, Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae)

The egg parasitoid Trichogramma spp. is an important biological control agent used against multiple species of Lepidopteran pest in forestry and agriculture. Due to the importance of Trichogramma spp. in biocontrol programs, its biological characteristics have been studied in detail, and current investigations should focus on the molecular biology of these tiny parasitoids. Real-time quantitative PCR (qPCR) is considered as the standard method for quantifying the gene expression of organisms. Surprisingly, the appropriate reference genes to ensure robust qPCR have not been documented at all for the Trichogramma genus. This study aimed to identify suitable reference genes for use in qPCR procedure of Trichogramma dendrolimi. Nine candidate housekeeping genes, namely glyceraldehyde-3-phosphate dehydrogenase (GAPDH), forkhead box O (FOXO), superoxide dismutase (SOD), beta-actin (ACTIN), ribosomal protein L10a (RPL10a), L18 (RPL18), L28 (RPL28), S13 (RPS13), and S15 (RPS15), were tested for their suitability as reference genes for developmental stage (3rd, 4th, 5th, 6th, 7th, 8th, 9th, and 10th day after parasitization), tissue (head, thorax, and abdomen of adults), sex of adults (male and female), and temperature (17 {degrees}C, 25 {degrees}C, and 32 {degrees}C). According to the GeNorm analysis, robust analysis should involve using an appropriate combination of reference genes, namely, at least three genes for different development stages, two genes for different tissues, two genes for different sex, and two genes for different temperature, respectively. According to the RelFinder method and by assessing the integrated values from using the {Delta}Ct method, GeNorm, NormFinder, and BestKeeper, we identified the developmental stage-specific reference genes SOD, GAPDH, and ACTIN; tissue-specific reference genes RPL18 and RPS15; sex-specific reference genes SOD and RPL18; and temperature-specific reference genes RPL18 and RPL10. When testing the use of stable vs. unstable reference genes, the substantial differences were observed in the estimation expression of a hypothetical target gene, HSP90, in response to temperature. The present study provides a robust method for the measurement of gene expression in T. dendrolimi and will be helpful for future biological control programs using Trichogramma wasps.

zoology↗

ORBIT for E. coli: Kilobase-scale oligonucleotide recombineering at high throughput and high efficiency

Microbiology and synthetic biology depend on reverse genetic approaches to manipulate bacterial genomes; however, existing methods require molecular biology to generate genomic homology, suffer from low efficiency, and are not easily scaled to high throughput applications. To overcome these limitations, we developed a system for creating kilobase-scale genomic modifications that uses DNA oligonucleotides to direct the integration of a non-replicating plasmid. This method, Oligonucleotide Recombineering followed by Bxb-1 Integrase Targeting (ORBIT) was pioneered in Mycobacteria, and here we adapt and expand it for E. coli. Our redesigned plasmid toolkit achieved nearly 1000x higher efficiency than {lambda} Red recombination and enabled precise, stable knockouts (<134 kb) and integrations (<11 kb) of various sizes. Additionally, we constructed multi-mutants (double and triple) in a single transformation, using orthogonal attachment sites. At high throughput, we used pools of targeting oligonucleotides to knock out nearly all known transcription factor and small RNA genes, yielding accurate, genome-wide, single mutant libraries. By counting genomic barcodes, we also show ORBIT libraries can scale to thousands of unique members (>30k). This work demonstrates that ORBIT for E. coli is a flexible reverse genetic system that facilitates rapid construction of complex strains and readily scales to create sophisticated mutant libraries.

microbiology↗

Seq-Scope Protocol: Repurposing Illumina Sequencing Flow Cells for High-Resolution Spatial Transcriptomics

Spatial transcriptomics (ST) technologies represent a significant advance in gene expression studies, aiming to profile the entire transcriptome from a single histological slide. These techniques are designed to overcome the constraints faced by traditional methods such as immunostaining and RNA in situ hybridization, which are capable of analyzing only a few target genes simultaneously. However, the application of ST in histopathological analysis is also limited by several factors, including low resolution, a limited range of genes, scalability issues, high cost, and the need for sophisticated equipment and complex methodologies. Seq-Scope--a recently developed novel technology--repurposes the Illumina sequencing platform for high-resolution, high-content spatial transcriptome analysis, thereby overcoming these limitations. Here we provide a detailed step-by-step protocol to implement Seq-Scope with an Illumina NovaSeq 6000 sequencing flow cell that allows for the profiling of multiple tissue sections in an area of 7 mm x 7 mm or larger. In addition to detailing how to prepare a frozen tissue section for both histological imaging and sequencing library preparation, we provide comprehensive instructions and a streamlined computational pipeline to integrate histological and transcriptomic data for high-resolution spatial analysis. This includes the use of conventional software tools for single cell and spatial analysis, as well as our recently developed segmentation-free method for analyzing spatial data at submicrometer resolution. Given its adaptability across various biological tissues, Seq-Scope establishes itself as an invaluable tool for researchers in molecular biology and histology. KEY POINTSO_LIThe protocol outlines a method for repurposing an Illumina NovaSeq 6000 flow cell as a spatial transcriptomics array, enabling the generation of high-resolution spatial datasets. C_LIO_LIThe protocol introduces a streamlined data analysis pipeline that produces a spatial digital gene expression matrix suitable for various single-cell and spatial transcriptome analysis methods. C_LIO_LIThe protocol allows for the capture of histology images from the same tissue section subjected to spatial transcriptomics analysis and allows users to precisely align the transcriptome dataset with the histological image using fiducial marks engraved on the flow cell surface. C_LIO_LILeveraging commonly available Illumina equipment, the protocol offers researchers ultra-high submicrometer resolution in spatial transcriptomics analysis with a comprehensive pipeline, rapid turnaround, cost efficiency, and versatility. C_LI

genomics↗

Atomic force microscopy reveals new biomarkers for monitoring subcellular changes in oxidative injury: neuroprotective effects of quercetin at the nanoscale

Oxidative stress is a process involved in the pathogenesis of many diseases, including atherosclerosis, hypertension, diabetes, Alzheimers disease etc. The biomarkers for assessing the degree of oxidative stress have been attracting much interest because of their potential clinical relevance in understanding cellular effects of free radicals and evaluation of the efficacy of drug treatment. Here, an interdisciplinary approach using atomic force microscopy (AFM) and cellular and biological molecular methods were used to obtain new potential biomarkers for monitoring oxidative stress condition. Biological methods confirmed the oxidative damage of investigated P19 neurons and revealed the underlying mechanism of quercetin protective action. AFM was employed to evaluate morphological (roughness) and nanomechanical (elasticity) properties that may be specific biomarkers for oxidative stress-induced cytoskeletal reorganization manifested by changes in the lateral dimension and height of neuronal somas. The morphological and nanomechanical analysis of neurons showed the strong mutual correlation between changes in cell membrane elasticity and neuroprotective effects of quercetin. Our findings indicate that AFM is a highly valuable tool for biomedical applications, detection and clarifying of drug-induced changes at the nanoscale and emphasize the potential of AFM approach in the development of novel therapeutic strategies directed against oxidative stress-induced neurodegeneration.

biophysics↗

ChassiDex: A microbial database useful for synthetic biology applications

ChassiDex is an open-source, non-profit online host organism database that houses a repository of molecular, biological and genetic data for model organisms with applications in synthetic biology. The structured user-friendly environment makes it easy to browse information. The database consists of a page for each model organism subdivided into sections such as Growth Characteristics, Strain diversity, Culture sources, Maintenance protocol, Transformation protocol, BioBrick parts and commonly used vectors. With tools such as CUTE built for codon usage table generator, it is also easy to generate and download accurate novel codon tables for unconventional hosts in suitable formats. This database was built as a project for the International Genetically Engineered Machine Competition in 2017 with the mission of making it easy to shift from working with one host organism to another unconventional host organism for any researcher in the field of synthetic biology. The code along with other instructions for the usage of the database and tools are publicly available at the GitHub page. We encourage the synthetic biology community to contribute to the database by adding data for any additional or existing host organism.\n\nhttps://chassidex.org; https://github.com/ChassiDex

synthetic biology↗

Dynamical rearrangement of human epidermal growth factor receptor 2 upon antibody binding: effects on the dimerization

Human epidermal growth factor 2 (HER2) is a ligand-free tyrosine kinase receptor of the HER family that is overexpressed in some of the most aggressive tumours. Treatment of HER2+ breast cancers with the humanized monoclonal anti-HER2 antibody (Trastuzumab) revealed highly effective, encouraging the development of various HER2-specific antibodies, kinase inhibitors and dimerization inhibitors for cancer therapy. Although it is known that HER2 dimerization involves a specific region of its extracellular domain, the so-called \"dimerization arm\", the mechanism of dimerization inhibition remains uncertain. However, uncovering how antibody interactions lead to inhibition of HER2 dimerization is of key importance in understanding its role in tumour progression and therapy. Herein, we employed several computational modelling techniques for a molecular-level understanding of the interactions between HER and specific anti-HER2 antibodies, namely an antigen-binding (Fab) fragment (F0178) and a single chain variable fragment from Trastuzumab (scFv). Specifically, we investigated the effects of antibody-HER2 interactions on the key residues of \"dimerization arm\" from molecular dynamics (MD) simulations of unbound HER (in a total of 1 {micro}s), as well as scFv:HER2 and F0178:HER2 complexes (for a total of 2.5 {micro}s). A deep surface analysis of HER receptor revealed that the binding of specific anti-HER2 antibodies induced conformational changes both in the interfacial residues, which was expected, and in the ECDII, in particular at the \"dimerization arm\", which is critical in establishing protein-protein interface (PPI) interactions. Our results support and advance the knowledge on the already described trastuzumab effect on blocking HER2 dimerization through synergistic inhibition and/or steric hindrance. Furthermore, our approach offers a new strategy for fine-tuning target activity through allosteric ligands.\n\nAuthor summaryIncreasing insight into the genetics and molecular biology of diseases has resulted in the identification of a high number of potential molecular targets for drug discovery and development. Human Epidermal Growth Factor Receptor 2 (HER2) is one of the most relevant Epidermal Growth Factor Receptor (EGFR) members, whose overexpression has been shown to play an important role in the development and progression of certain aggressive types of breast cancer. Thus, the development of novel approaches on anti-HER2 therapies is quiet relevant. Molecular modelling and simulation can be used to bring new perspectives, both in structure-based drug design and to provide atomistic information of the intermolecular coupling dynamics between inhibitors and receptors via interactive computographic software. Considering my interest in drug design and mechanisms of action using integrated in silico approaches, herein, I have used multiple methods to evaluate how HER2 coupling to its different partners could alter this functional mechanism. The results suggest that the antibodies fragments studied show different dynamic complexes with HER2 although both could contribute to downstream of the tumour cell receptor pathways. I do believe that future research breakthroughs with aid of chemo-bioinformatics will allow a more comprehensive perception on biomedicine.

bioinformatics↗

Complete Mutagenesis of the Genome and Proteome of {Phi}X174

The bacteriophage {Phi}X174 was the first genome to be sequenced and the first to be chemically synthesised. Here we present a complete map of the consequences of changing every nucleotide in the {Phi}X174 genome and every amino acid in the proteome. In total, half of nucleotide and >60% of amino acid changes impair fitness. However, this varies substantially across proteins and non-coding regions. Surprisingly, the most important mechanistic cause of reduced fitness is disruption of protein interaction interfaces, accounting for nearly half of detrimental protein variants. A further one quarter of damaging variants disrupt protein cores but one in four lack a mechanistic explanation. Mutational effects are only moderately-well predicted by state-of-the-art artificial intelligence models, but, combined with structural modelling, provide mechanistic hypotheses and insights into the DNA replication machinery. This complete mutagenesis of a biological system quantifies the limits of our current understanding of, and ability to predict, molecular biology.

genomics↗

Induction of an immortalized songbird cell line allows for gene characterization and knockout by CRISPR-Cas9

The zebra finch is a powerful model for several biological fields, particularly neuroscience and vocal communication. However, this species lacks a robust cell line for molecular biology research and reagent optimization. Here we describe a cell line, CFS414, generated from zebra finch embryonic fibroblasts using the SV40 large and small T antigens. This cell line demonstrates an improvement over previous songbird cell lines through continuous and density-independent growth, allowing for indefinite culture and monoclonal line derivation. Cytogenetic, genomic, and transcriptomic profiling established the provenance of this cell line and identified the expression of genes relevant to ongoing songbird research. Using this cell line, we demonstrated a stress-dependent localization response of the zebra finch song nuclei specialized gene, SAP30L, and disrupted endogenous gene sequences using S.aureus Cas9. The utility of this cell line enhances the molecular potential of the zebra finch and validates cell immortalization strategies in a songbird species.

cell biology↗

BOTany Methods: Accessible Automation for Plant Synthetic Biology

Most members of the synthetic biology community, particularly plant scientists, lack access to liquid handling robots to scale up experiments, enhance reproducibility, and accelerate the Design, Build, Test, Learn cycle. Biofoundries enable high throughput data acquisition to train AI models and to develop new bioproducts, but they are capital-intensive to set up and not widely distributed. Entry-level, 3D-printed robots offer more affordable alternatives, but suffer from a shortage of validated protocols that can be modified without prior coding experience. To enhance access to biological automation, we developed a collection of modular BOTany Methods using Opentrons OT-2 robots to streamline the most common methods for molecular biology research and education. Our comprehensive workflow offers automation for a variety of procedures, ranging from simple but repetitive tasks (such as primer dilution and PCR setup) to more complex operations, including Plant Modular Cloning (MoClo), bacterial transformation, and plasmid extraction. Our BOTany Methods enable undergraduate students and other early career researchers to run designer experiments using table-based inputs, without editing the custom Python scripts. This pipeline enables end-to-end molecular cloning with minimal user intervention, enhancing throughput and traceability for synthetic biology applications. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/671538v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@1b98282org.highwire.dtl.DTLVardef@2727bdorg.highwire.dtl.DTLVardef@a2157borg.highwire.dtl.DTLVardef@1305107_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

The basal level of gene expression associated with chromatin loosening shapes Waddington landscapes and controls cell differentiation

The baseline level of transcription is variable and seriously complicates the normalization of comparative transcriptomic data, but its biological importance remains unappreciated. We show that this ingredient is in fact crucial for the interpretation of molecular biology results. It is correlated to the degree of chromatin loosening measured by DNA accessibility, and systematically leads to cellular dedifferentiation as assessed by transcriptomic signatures, irrespective of the molecular and cellular tools used. A theoretical analysis of gene circuits formally involved in differentiation, reveals that the epigenetic landscapes of Waddington are restructured by the level of non-specific expression, such that the attractors of progenitor and differentiated cells can be mutually exclusive. Together, these results unveil a generic principle of epigenetic landscape remodeling in which the basal gene expression level, notoriously important in pluripotent cells, allows the maintenance of stemness by generating a specific landscape and in turn, its reduction favors multistability and thereby differentiation. This study highlights how heterochromatin maintenance is essential for preventing pathological cellular reprogramming, age-related diseases and cancer.

cell biology↗

Pyroptosis-associated molecular classification and prognostic signature in glioma

Integrative analysis was performed in the Chinese Glioma Genome Atlas and The Cancer Genome Atlas to describe the pyroptosis-associated molecular classification and prognostic signature in glioma. Pyroptosis-related genes were used for consensus clustering and to develop a prognostic signature. The immune statuses, molecular alterations and clinical features of differentially expressed genes were analyzed among different subclasses and risk groups. A lncRNA-miRNA-mRNA network was built, and drug sensitivity analysis was used to identify small molecular drugs for the identified genes. Glioma can be divided into two subclasses using 30 pyroptosis-related genes. Cluster 1 displayed high immune signatures and poor prognosis as well as high immune-related function scores. A prognostic signature based on 15 pyroptosis-related genes of the CGGA cohort can predict the overall survival of glioma and was well validated in the TCGA cohort. Cluster 1 had higher risk scores. The high-risk group had high immune cell and function scores and low DNA methylation of pyroptosis-related genes. The differences in pyroptosis-related gene mutations and somatic copy numbers were significant between the high-risk and low-risk groups. The ceRNA regulatory network uncovered the regulatory patterns of different risk groups in glioma. Nine pairs of target genes and drugs were identified. In vitro, CASP8 promotes the progression of glioma cells. Pyroptosis-related genes can reflect the molecular biological and clinical features of glioma subclasses. The established prognostic signature can predict prognosis and distinguish molecular alterations in glioma patients. Our comprehensive analyses provide valuable guidelines for improving glioma patient management and individualized therapy.

cancer biology↗

Phylogenomic prediction of interaction networks in the presence of gene duplication

Assigning gene function from genome sequences is a rate-limiting step in molecular biology research. A proteins position within an interaction network can potentially provide insights into its molecular mechanisms. Phylogenetic analysis of evolutionary rate covariation (ERC) in protein sequence has been shown to be effective for large-scale prediction of functional relationships and interactions. However, gene duplication, gene loss, and other sources of phylogenetic incongruence are barriers for analyzing ERC on a genome-wide basis. Here, we developed ERCnet, a bioinformatic program designed to overcome these challenges, facilitating efficient all- vs-all ERC analyses for large protein sequence datasets. We simulated proteome datasets and found that ERCnet achieves combined false positive and negative error rates well below 10% and that our novel branch-by-branch length measurements outperforms root-to-tip approaches in most cases, offering a valuable new strategy for performing ERC. We also compiled a sample set of 35 angiosperm genomes to test the performance of ERCnet on empirical data, including its sensitivity to user-defined analysis parameters such as input dataset size and branch-length measurement strategy. We investigated the overlap between ERCnet runs with different species samples to understand how species number and composition affect predicted interactions and to identify the protein sets that consistently exhibit ERC across angiosperms. Our systematic exploration of the performance of ERCnet provides a roadmap for design of future ERC analyses to predict functional interactions in a wide array of genomic datasets. ERCnet code is freely available at https://github.com/EvanForsythe/ERCnet.

genomics↗

Genomic Tokenizer: Toward a biology-driven tokenization in transformer models for DNA sequences

SummaryTransformer models are revolutionizing sequence analysis across various domains, from natural language processing to genomics. These models rely on tokenizers to split input sequences into manageable chunks -- a straightforward task in natural language but more challenging for long DNA sequences that lack distinct "words." Most biological tokenizers are data-driven and do not align with the "central dogma of molecular biology": DNA is transcribed into RNA, which is then translated into proteins, with each three-letter codon specifying a particular amino acid, some of which are synonymous for the amino acids they represent. Start codons signal the beginning of protein synthesis, while stop codons signal its termination. The Genomic Tokenizer (GT) incorporates this biological process flow into a standard tokenizer interface within the HuggingFace transformer package. GT can be used to pre-train foundational transformer models on DNA sequences. We compare the performance of GT with two alternate tokenization strategies and discuss its potential applications. Availability and implementationThe source code of GT is available from https://github.com/dermatologist/genomic-tokenizer under the MPL-2.0 license. It can be installed from Python Package Index (PyPI) and used as a tokenizer in transformer model training pipelines.

bioinformatics↗

Thermodynamic Projection Of The Antibody Interaction Network: The Binding Fountain Energy Landscape

The complexity of the adaptive immune system in humans is comparable to that of the central nervous system in terms of cell numbers, cellular diversity and the network of interactions between components. While the application of molecular biological methods and bioinformatics has brought about an ever deepening and sharpening static description of the molecular and cellular components of the system, a unifying theoretical understanding of the laws governing the dynamics of the system is still lacking.\n\nWe have recently developed a quantitative model for the description of antibody homeostasis as defined by the dimensions of antigen concentration, antigen-antibody interaction affinity and antibody concentration. In this paper we develop the concept of a novel thermodynamic representation of multiple molecular interactions in a system, the fountain energy landscape of binding. We show that the hypersurface of the binding fountain corresponds to the antibody-antigen interaction network projected onto an energy landscape defined by conformational entropy and free energy of binding. We demonstrate that thymus independent and thymus dependent antibody responses show distinct patterns of changes in the energy landscape. Overall, the binding fountain energy landscape concept allows a systems biological, thermodynamic perception of the functioning of the clonal humoral immune system.

biophysics↗