scholarly journals Biochemical and Pharmacological Characterization of TLBbar, a New Serine Protease with Coagulant Activity from Bothrops barnetti Snake Venom

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
Magaly Alejandra Brousett-Minaya ◽  
Paulo Aparecido Baldasso ◽  
Salomón Huancahuire-Vega ◽  
Sérgio Marangoni

A thrombin-like enzyme named TLBbar was isolated from Bothrops barnetti snake venom and its biochemical and pharmacological characteristics were determined. TLBbar was purified using size exclusion chromatography and reverse phase HPLC, showing molecular mass of 28750.7 Da determined by mass spectrometry. TLBbar serine protease is basic (pI 7.4) and its structure shows similarity with other serine proteases of snake venom. Optimal proteolytic activity was at 37°C and pH 8; this activity was strongly inhibited by PMSF and Leupeptin, however; heparin, and soybean trypsin inhibitor (SBT-I) were ineffective. Kinetic studies on BApNA chromogenic substrate have revealed that TLBbar presents a Michaelis-Menten kinetics, with values of Km and Vmax of 0.433 mM and 0.42 nmol/min, respectively. TLBbar showed high clotting activity upon bovine and human plasma, presenting IC of 125 and minimum dose coagulant (MDC) of 2.23 μg/μL. TLBbar cleavages the Aα chain of bovine fibrinogen, with maximal efficiency at 30–40°C in the presence of calcium after two hours incubation; this fibronogenolityc activity was inhibited by PMSF and Leupeptin, confirming its classification in the group of serine proteases. In addition, TLBbar is capable of aggregating platelets in the same way that thrombin in concentrations of 2.5 μg/μL.

2004 ◽  
Vol 36 (12) ◽  
pp. 798-802 ◽  
Author(s):  
Débora F. Vieira ◽  
Leandra Watanabe ◽  
Carolina D. Sant'ana ◽  
Silvana Marcussi ◽  
Suely V. Sampaio ◽  
...  

Abstract A thrombin-like serine protease, jararassin-I, was isolated from the venom of Bothrops jararaca. The protein was obtained in high yield and purity by a single chromatographic step using the affinity resin Benzamidine-Sepharose CL-6B. SDS-PAGE and dynamic light scattering analyses indicated that the molecular mass of the enzyme was about 30 kD. The enzyme possessed fibrinogenolytic and coagulant activities. The jararassin-I degraded the Bβ chain of fibrinogen while the Aα chain and γ chain were unchanged. Proteases inhibitors, PMSF and benzamidine inhibited the coagulant activity. These results showed jararassin-I is a serine protease similar to coagulating thrombin-like snake venom proteases, but it specifically cleaves Bβ chain of bovine fibrinogen. Single crystals of enzyme were obtained (0.2 mm×0.2 mm×0.2 mm) and used for X-ray diffraction experiments.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 582
Author(s):  
Cristian Franco-Servín ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
Ramsés Alejandro Rosales-García ◽  
...  

The Baja California Peninsula has over 250 islands and islets with many endemic species. Among them, rattlesnakes are the most numerous but also one of the least studied groups. The study of island rattlesnake venom could guide us to a better understanding of evolutionary processes and the description of novel toxins. Crotalus helleri caliginis venom samples were analyzed to determine possible ontogenetic variation with SDS-PAGE in one and two dimensions and with RP-HPLC. Western Blot, ELISA, and amino-terminal sequencing were used to determine the main components of the venom. The biological and biochemical activities demonstrate the similarity of C. helleri caliginis venom to the continental species C. helleri helleri, with both having low proteolytic and phospholipase A2 (PLA2) activity but differing due to the absence of neurotoxin (crotoxin-like) in the insular species. The main components of the snake venom were metalloproteases, serine proteases, and crotamine, which was the most abundant toxin group (30–35% of full venom). The crotamine was isolated using size-exclusion chromatography where its functional effects were tested on mouse phrenic nerve–hemidiaphragm preparations in which a significant reduction in muscle twitch contractions were observed. The two Mexican antivenoms could neutralize the lethality of C. helleri caliginis venom but not the crotamine effects.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 362
Author(s):  
Sabrina Banella ◽  
Eride Quarta ◽  
Paolo Colombo ◽  
Fabio Sonvico ◽  
Antonella Pagnoni ◽  
...  

Pleural mesothelioma is a lung diffuse tumor, whose complete resection is unlikely. Consequently, metastases reappear where the primary tumor was removed. This paper illustrates the orphan medicine designation procedure of an intracavitary cisplatin film and related pharmaceutical development aspects requested by the European Medicines Agency (EMA) in its Scientific Advice. Since cisplatin pharmacokinetics from the implanted film in sheep resulted substantially modified compared to intravenous administration, the formation of a cisplatin/hyaluronan complex had been hypothesized. Here, the interaction between sodium hyaluronate (NaHA) and cisplatin (CisPt) was demonstrated. Size exclusion chromatography qualitatively evidenced the complex in the film-forming mixture, only showing the NaHA peak. Atomic absorption spectroscopy of the corresponding fraction revealed platinum, confirming the interaction. Reverse phase HPLC quantified about 5% free cisplatin in the film-forming mixture, indirectly meaning that 95% was complexed. Finally, a study of CisPt release from the film assessed how CisPt/NaHA complex affected drug availability. In water, a medium without chloride ions, there was no release and the film remained intact for 48 h and longer, whereas the placebo film dissolved in 15 min. In 0.9% NaCl medium, the film became more soluble, dissolving within 3–4 h. However, cisplatin release was still controlled by the existing complex in solution until chloride ions displaced it. While the film modified its dissolution with aging, CisPt release remained unaffected (90% released in 48 h).


Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 123-128
Author(s):  
Andréia S. Magaton ◽  
Teresa Cristina F. Silva ◽  
Jorge Luiz Colodette ◽  
Dorila Piló-Veloso ◽  
Flaviana Reis Milagres ◽  
...  

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.


2018 ◽  
Vol 2 ◽  
Author(s):  
Akika Ejima ◽  
Megumi Nakamura ◽  
Yasushi A. Suzuki ◽  
Kenji Sato

Bioactive peptides in the body after ingestion of plant protein hydrolysates have been speculated but not identified. We aimed to establish an approach to identify small amounts of food-derived peptides in humans after ingestion of non-extracellular matrix protein hydrolysates. Corn and wheat gluten hydrolysates were digested using pancreatin and leucine aminopeptidase; the resultant peptides were identified via size-exclusion chromatography and reverse-phase HPLC-tandem mass spectrometry (MS/MS). Structures of indigestible peptides were confirmed via LC-MS/MS in multi-reaction monitoring mode. All indigestible peptides in the exopeptidase digest were diprolyl and di- and tripyroglutamyl peptides. Blood collected from healthy volunteers (n = 4) before and after ingestion of 9 g of the hydrolysates was assessed for the indigestible peptides via LC-MS/MS. Six peptides (Pro-Ala, Pro-Gly, Pro-Gln, pyroGlu-Pro, pyroGlu-Leu-Pro, and pyroGlu-Gln-Pro) significantly increased in human plasma up to 10–100 nM compared to the baseline. This may hence be a powerful tool for identifying foodderived peptides in blood.


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