Biology subjects

Oganesyan, I.

Publications and source records attributed to Oganesyan, I..

3 recordsLinked to original sources

bioRxiv2022

Prototyping of a lateral flow assay based on monoclonal antibodies for detection of Bothrops venoms

BackgroundBrazil is home to a multitude of venomous snakes, perhaps the most medically relevant of which belong to the Bothrops genus. Bothrops spp. are responsible for roughly 70% of all snakebites in Brazil, and envenomings caused by their bites can be treated with three types of antivenom: bothropic antivenom, bothro-lachetic antivenom, and bothro-crotalic antivenom. The choice in antivenom that is administered depends not only on its availability and how certain the treating physician is that the patient was bitten by a bothropic snake. The diagnosis of a bothropic envenoming can be made based on expert identification of a photo of the snake or based on a syndromic approach wherein the clinician examines the patient for characteristic manifestations of envenoming. This approach can be very effective but requires staff that has been trained in clinical snakebite management, which, unfortunately, far from all relevant staff has. ResultsIn this paper, we describe a prototype of the first lateral flow assay (LFA) capable of detecting venoms from Brazilian Bothrops spp. The monoclonal antibodies for the assay were generated using hybridoma technology and screened in sandwich enzyme-linked immunosorbent assays (ELISAs) to identify Bothrops spp. specific antibody sandwich pairs. The sandwich pairs were used to develop a prototype LFA that was able to detect venom from several different Bothrops spp. The limit of detection (LoD) of the prototype was evaluated using Brazilian B. atrox whole venom and was determined to be 8.0 ng/mL in spiked serum samples and 9.5 ng/mL in spiked urine samples, when using a portable reader, and < 25 ng/mL in spiked buffer when reading by eye. SignificanceThe work presented here serves as a proof of concept of a genus-specific venom detection kit, which could support physicians in diagnosing Bothrops envenomings. Although further optimization and testing is needed before the LFA can find clinical use, such a device could aid in decentralizing antivenoms in the Brazilian Amazon and help ensure optimal snakebite management for even more victims of this highly neglected disease.

immunology↗

bioRxiv2022

Discovery of a broadly-neutralizing human antibody that can rescue mice challenged with neurotoxin-rich snake venoms

Snakebite envenoming continues to claim many lives across the globe, necessitating the development of improved therapies. To this end, human monoclonal antibodies may possess advantages over current plasma-derived antivenoms by offering superior safety and improved neutralization capacity. However, as new antivenom products may need to be polyvalent, i.e., target multiple different snake species, without dramatically increasing dose or cost of manufacture, such monoclonal antibodies need to be broadly-neutralizing. Here, we report the establishment of a pipeline for the discovery of high affinity broadly-neutralizing human monoclonal antibodies. We further demonstrate its utility by discovering an antibody that can prevent lethality induced by N. kaouthia whole venom at an unprecedented low molar ratio of one antibody per toxin, and which also prolongs survival of mice injected with Dendroaspis polylepis or Ophiophagus hannah whole venoms.

bioengineering↗

bioRxiv2020

Conformational dynamics of -synuclein during the interaction with phospholipid nanodiscs by Millisecond Hydrogen Deuterium Exchange Mass Spectrometry

Both normal and pathological functions of -synuclein (SN), an abundant protein in the central and peripheral nervous system, have been linked to its interaction with membrane lipid bilayers. The ability to characterize structural transitions of SN upon membrane complexation will clarify molecular mechanisms associated with SN-linked pathologies, including Parkinsons disease (PD), Multiple Systems Atrophy and other synucleinopathies. In this work, Time-Resolved ElectroSpray Ionization Hydrogen/ Deuterium Exchange Mass Spectrometry (TRESI-HDX-MS) was employed to acquire a detailed picture of SNs conformational transitions as it undergoes complexation with nanodisc membrane mimics. Using this approach, SN interactions with DMPC nanodiscs were shown to be rapid exchanging and to have a little impact on the SN conformational ensemble. Interactions with nanodiscs containing lipids known to promote amyloidogenesis (e.g., POPG), on the other hand, were observed to induce substantial and specific changes in the SN conformational ensemble. Ultimately, we identify a region corresponding residues 19-28 and 45-57 of the SN sequence that is uniquely impacted by interactions with amyloidogenic lipid membranes and may therefore play a critical role in pathogenic aggregation.

biochemistry↗