Biology subjects

Nalbantsoy, A.

Publications and source records attributed to Nalbantsoy, A..

4 recordsLinked to original sources

bioRxiv2024

Venomics and Peptidomics of Palearctic vipers: Clade-wide analysis of seven taxa of the genera Vipera, Montivipera, Macrovipera and Daboia across Türkiye

Snake venom variations are a crucial factor to understand the consequences of snakebite envenoming worldwide and therefore its important to know about toxin composition alterations between taxa. Palearctic vipers of the genera Vipera, Montivipera, Macrovipera and Daboia have high medical impacts across the Old World. One hotspot for their occurrence and diversity is Turkiye on the border between the continents, but many of their venoms remain still understudied. Here, we present the venom compositions of seven Turkish viper taxa. By complementary mass spectrometry-based bottom-up and top-down workflows, the venom profiles were investigated on proteomics and peptidomics level. This study includes the first venom descriptions of Vipera berus barani, Vipera darevskii, Montivipera bulgardaghica albizona and Montivipera xanthina, as well as first snake venomics profiles of Turkish Macrovipera lebetinus obtusa and Daboia palaestinae, including an in-depth reanalysis of Montivipera bulgardaghica bulgardaghica venom. Additionally, we identified the modular consensus sequence pEXW(PZ1-2P(EI)/(KV)PPLE for bradykinin-potentiating peptides (BPP) in viper venoms. For better insights into variations and potential impacts of medical significance the venoms were compared against other Palearctic viper proteomes, including the first genus-wide Montivipera venom comparison. This will help the risk assessment of snakebite envenoming by these vipers and aid in predicting the venoms pathophysiology and clinical treatments.

molecular biology↗

bioRxiv2019

Extended snake venomics by top-down in-source decay: Investigating the newly discovered Anatolian Meadow viper subspecies, Vipera anatolica senliki

Herein we report on the venom proteome of Vipera anatolica senliki, a recently discovered and hitherto unexplored subspecies of the critically endangered Anatolian Meadow viper endemic to the Antalya Province of Turkey. Integrative venomics, including venom gland transcriptomics as well as complementary bottom-up and top-down proteomic analyses, were applied to fully characterize the venom of V. a. senliki. Furthermore, the classical top-down venomics approach was extended to elucidate the venom proteome by an alternative in-source decay (ISD) proteomics workflow using the reducing matrix 1,5-diaminonaphthalene (1,5-DAN). Top-down ISD proteomics allows for disulfide bond mapping as well as effective de novo identification of high molecular weight venom constituents, both of which are difficult to achieve by commonly established top-down approaches. Venom gland transcriptome analysis identified 42 venom transcript annotations from 13 venom toxin families. Relative quantitative snake venomics revealed snake venom metalloproteinases (svMP, 42.9%) as the most abundant protein family, followed by several less dominant toxin families. Online mass profiling and top-down venomics provide a detailed insight into the venom proteome of V. a. senliki and facilitates a comparative analysis of venom variability for the closely related subspecies, V. a. anatolica.\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=60 SRC=\"FIGDIR/small/773606v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (35K):\norg.highwire.dtl.DTLVardef@2e26ecorg.highwire.dtl.DTLVardef@1fd6bbeorg.highwire.dtl.DTLVardef@ac8f25org.highwire.dtl.DTLVardef@e9ea62_HPS_FORMAT_FIGEXP M_FIG TOC Figure C_FIG

biochemistry↗

bioRxiv2018

Community venomics reveals intra-species variations in venom composition of a local population of Vipera kaznakovi in Northeastern Turkey

We report on the variable venom composition of a population of the Caucasus viper (Vipera kaznakovi) in Northeastern Turkey. We applied a combination of venom gland transcriptomics, as well as de-complexing bottom-up and top-down venomics, enabling the comparison of the venom proteomes from multiple individuals. In total, we identified peptides and proteins from 15 toxin families, including snake venom metalloproteinases (svMP; 37.8%), phospholipases A2 (PLA2; 19.0%), snake venom serine proteinases (svSP; 11.5%), C-type lectins (CTL; 6.9%) and cysteine-rich secretory proteins (CRISP; 5.0%), in addition to several low abundant toxin families. Furthermore, we identified intra-species variations of the V. kaznakovi venom composition, and find these were mainly driven by the age of the animals, with lower svSP abundance in juveniles. On a proteoform level, several small molecular weight toxins between 5 and 8 kDa in size, as well as PLA2s, drove the difference between juvenile and adult individuals. This study provides first insights into venom variability of V. kaznakovi and highlights the utility of intact mass profiling for a fast and detailed comparison of snake venoms of individuals from a community.\n\nBiological SignificancePopulation level and ontogenetic venom variation (e.g. diet, habitat, sex or age) can cause a loss of antivenom efficacy against snake bites from wide ranging snake populations. The state of the art for the analysis of snake venoms are de-complexing bottom-up proteomics approaches. While useful, these have the significant drawback of being time-consuming and following costly protocols, and consequently are often applied to pooled venom samples. To overcome these shortcomings and to enable rapid and detailed profiling of large numbers of individual venom samples, we integrated an intact protein analysis workflow into a transcriptomics-guided bottom-up approach. The application of this workflow to snake individuals of a local population of V. kaznakovi revealed intra-species variations in venom composition, which are primarily explained by the age of the animals, and highlighted svSP abundance to be one of the molecular drivers for the compositional differences.\n\nHighlightsO_LIFirst community venomic analysis of a local population of the Caucasian viper (Vipera kaznakovi).\nC_LIO_LIThe venom gland transcriptome of V. kaznakovi identified 46 toxin genes relating to 15 venom toxin families.\nC_LIO_LIBottom-up venomics revealed the identification of 25 proteins covering 7 toxin families mainly dominated by snake venom metalloproteinases (svMP).\nC_LIO_LICommunity venomics by top-down mass profiling revealed ontogenetic shifts between juvenile and adult snakes.\nC_LI

biochemistry↗

bioRxiv2018

Investigating the cytotoxic effects of the venom proteome of two species of the Viperidae family (Cerastes cerastes and Cryptelytrops purpureomaculatus) from various habitats

Animal secretions are of great interest in terms of drug development due to their complex protein and peptide composition. Especially, in the field of therapeutic medications such as anti-cancer drugs snake venoms receive attention. In this study we report of two Viperidae species from various habitats with a particular focus on the cytotoxic potential along with the decomplexation of the venom proteome: the horned desert viper (Cerastes cerastes), native to desert regions of North Africa and the mangrove pit viper (Cryptelytrops purpureomaculatus), found in coastal forests of Southeast Asia. Initial cytotoxic screenings of the crude venoms revealed diverse activity, with the highest effect against SHSY5Y human glioblastoma carcinoma cells compared to other cancerous and non-cancerous cell lines. In-depth cytotoxicity studies of SHSY5Y cells with purified venom fractions revealed dimeric disintegrins from C. cerastes venom which exerted a high cytotoxic activity with IC50 values from 0.11 to 0.58{micro}M and the disintegrins-like effect on SHSY5Y morphology was observed due to cell detachment. Furthermore, two polyproline BPP-related peptides, one PLA2 and a peptide-rich fraction were determined for C. purpureomaculatus with moderate IC50 values between 3-51{micro}M. Additionally, the decryption of the venom proteomes by snake venomic mass spectrometry and comparison of same species from different habitats revealed slight differences in the composition.

biochemistry↗