Botrocetin is a heterodimer snake venom protein that induces von Willebrand factor (VWF)- and platelet glycoprotein Ib (GPIb)-dependent platelet agglutination in vitro. We have cloned cDNAs for a botrocetin-2 from a cDNA library of the venom gland of Bothrops jararaca having a high similarity with botrocetin subunits. Recombinant botrocetin-2, expressed in 293T cells, showed cofactor activity comparable to natural botrocetin. In a single subunit expression experiment, a dimer of the β subunit was obtained, and it showed reduced, but apparent, platelet agglutination activity. Ala scanning mutagenesis showed that substitutions at Asp62, Asp70, Arg115, or Lys117 in the β subunit reduced platelet agglutination activity. The 3D homology modeling of botrocetin-2 complexed with the VWF A1 domain and GPIbα indicated that Asp62, Arg115, and Lys117 of the β subunit are located near Arg218 and Asp222 of GPIbα, respectively, and that Aspβ70 is in proximity to Gln1391 of the A1 domain. Our results indicate that these charged amino acid residues in the β subunit have a preferential role in the activity of botrocetin-2. Since it has been time-consuming and difficult to obtain homogeneous botrocetin from natural venom, recombinant botrocetin-2 has potential benefits for clinical and basic investigations into hemostasis and thrombosis as a standard reagent.
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http://dx.doi.org/10.1021/bi300442c | DOI Listing |
Vet World
November 2024
School of Veterinary Medicine, National University of Loja (UNL), Loja 1101608, Ecuador.
Background And Aim: Leptospirosis is an infectious zoonotic disease that significantly affects animal health, particularly the reproduction of ruminants. However, some aspects of epidemiology and clinical characteristics have not been clarified. This study aimed to estimate the prevalence and identify risk factors of leptospirosis in female bovines at reproductive age in the Ecuadorian Amazon rainforest.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Clinical Laboratory, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, Affiliated Cancer Hospital of University of Electronic Science and Technology of China, Chengdu, People's Republic of China.
The aim of this study was to investigate the role of platelet indicators in the susceptibility of ABO blood groups to lung adenocarcinoma. This was a multicenter retrospective cohort analysis. The study included 528 patients diagnosed with primary lung adenocarcinoma and 528 randomly selected control group patients who were admitted to the Chengdu Fifth People's Hospital from January 2021 to September 2023.
View Article and Find Full Text PDFJ Thromb Haemost
January 2025
Division of Hematology, Departments of Internal Medicine and Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA. Electronic address:
Background: Genetically determined amino acid substitutions in the platelet adhesive A1 domain alter von Willebrand factor's (VWF) platelet agglutination competence, resulting in both gain- (type 2B) and loss-of-function (type 2M) phenotypes of von Willebrand disease. Prior studies of variants in both phenotypes revealed defects in secondary structure that altered stability and folding of the domain. An intriguing observation was that loss of function arose from both misfolding of A1 and, in a few cases, hyperstabilization of the native structure.
View Article and Find Full Text PDFChem Biodivers
November 2024
College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550004, People's Republic of China.
Thirty-eight novel butylphthalide-hydroxycinnamic acid hybrid derivatives were designed and synthesized to discover effective antiplatelet agglutination drugs. Among these compounds, 3 o gave the optimal inhibitory activity against AA-induced platelet aggregation in vitro and also exhibited better inhibition than the precursor 3-n-butylphthalide (NBP) against thrombin-induced platelet contraction, carrageenan-induced tail thrombosis, and FeCl-induced common carotid artery thrombosis. Further investigations on the anti-ischemic stroke activity revealed that compound 3 o exhibited a remarkable protective effect against ischemic/reperfusion brain injury.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Spine Surgery, The 940th Hospital of Joint Logistics Support Force of Chinese PLA, Lanzhou, Gansu, China.
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