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Lelenaite, I.

Publications and source records attributed to Lelenaite, I..

4 recordsLinked to original sources

High-throughput microarray analysis provides new insight into optimising Rubisco yield from diverse plants

Interest in plant-based proteins is increasing due to environmental, ethical, and health considerations. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the most abundant protein on Earth, is present in all green leafy biomass and possesses excellent nutritional and functional properties. Despite its potential, Rubisco remains underutilised because extraction methods are often costly, inefficient, and influenced by species-specific differences. Moreover, the impact on Rubisco yield of cell wall-protein interactions remains poorly understood. We applied Microarray Polymer Profiling (MAPP), a high-throughput platform for simultaneous polysaccharide and protein mapping, to characterise diverse leafy biomass sources. This approach revealed interspecies variation and glycan-protein interactions that influence protein extractability and these insights inform biomass selection and optimisation of extraction protocols to improve Rubisco yield. MAPP was also used to evaluate the effects of carbohydrate-active enzymes on Rubisco recovery through targeted cell wall modification.

plant biology↗

A novel Flavobacterium quisquiliarum porphyrin binding protein independently disrupts Pseudomonas aeruginosa biofilms

Bacterial biofilms underpin chronic infection and antimicrobial resistance, notably in Pseudomonas aeruginosa. Here we deconvolute a commercial alginate lyase preparation from Flavobacterium quisquiliarum and identify a previously uncharacterised [~]21 kDa porphyrin-binding protein (FqPBP). Structural, biophysical and docking analyses reveal high-affinity tetrapyrrole binding. Recombinant FqPBP independently inhibits and disperses P. aeruginosa biofilms, implicating porphyrin sequestration and iron homeostasis in biofilm control and highlighting a potential therapeutic strategy targeting iron acquisition pathways.

microbiology↗

Unusual molecular architecture of a human gut microbiota beta-mannanase reveals a new CBM family

{beta}-mannans are plant structural and storage polysaccharides prevalent in the human diet. Their degradation in the gastrointestinal tract is mediated by the human gut microbiota (HGM) through expression of a plethora of carbohydrate-active enzymes (CAZymes), although our understanding of the details of mannan breakdown is lacking. In this study, a prominent HGM member, Bacteroides cellulosilyticus, was found to be exceptionally efficient at utilising {beta}-mannans, mediated by the expression of a single polysaccharide utilisation locus (PUL). Amongst the predicted surface CAZymes encoded in the PUL, we identified a family 26 glycoside hydrolase of an unusual molecular architecture. BcWH2_GH26 contains a putative carbohydrate-binding module (CBM) directly intercalated into its catalytic domain, unlike classical CBMs which are located at the N- or C-termini of the catalytic domain. Phylogenetic and functional analyses of this internal CBM, and a homologue from another mannan user Bacteroides uniformis, revealed a narrow specificity for {beta}-mannan and support their classification as a novel CBM family. To investigate the evolutionary basis for the unusual enzyme architecture, the effect of the CBM on the catalytic activity of the enzyme was assessed. No significant differences in the kinetic parameters were found between the full-length and CBM deletion constructs against both soluble and insoluble mannans. The potential role of the internal CBM in enzyme function is discussed in the context of the likely localisation of the BcWH2_GH26 in the outer membrane utilisome encoded by the Bc mannan PUL.

biochemistry↗

Structurally diverse calloses/β-1,3-glucans in plant cell wall microdomains

Cell walls underpin the mechanics of cell growth, intercellular signalling, and defence against pathogenic organisms. {beta}-(1,3)-glucans (also known as callose) are polysaccharides found in plants, fungi, and some bacterial species. In developing plant organs, callose accumulates around intercellular channels (plasmodesmata) controlling cell-to-cell communication. We developed monoclonal antibodies for the detection of {beta}-(1,3)-glucans and using these identified distinct populations of callose differing in size and secondary structure. Callose sub-populations were in proximal but not overlapping cell wall microdomains implying distinct spatial and functional microenvironments. We also unveiled callose interaction with xyloglucan; another plant glycan regulating cell wall functions. This work challenges previous views demonstrating structural heterogeneity in plant callose and supporting interactions between glycans with roles in the regulation of cell wall properties and functions.

plant biology↗