scholarly journals Bp-13 PLA2: Purification and Neuromuscular Activity of a New Asp49 Toxin Isolated fromBothrops pauloensisSnake Venom

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Georgina Sucasaca-Monzón ◽  
Priscila Randazzo-Moura ◽  
Thalita Rocha ◽  
Frank Denis Torres-Huaco ◽  
Augusto Vilca-Quispe ◽  
...  
Keyword(s):  
Contractile Response ◽  
Maximal Activity ◽  
Direct Electrical Stimulation ◽  
Terminal Sequence ◽  
Pharmacological Characterization ◽  
Neuromuscular Activity ◽  
Rp Hplc ◽  
Main Effect ◽  
High Degree

A new PLA2(Bp-13) was purified fromBothrops pauloensissnake venom after a single chromatographic step of RP-HPLC onμ-Bondapak C-18. Amino acid analysis showed a high content of hydrophobic and basic amino acids and 14 half-cysteine residues. The N-terminal sequence showed a high degree of homology with basic Asp49 PLA2myotoxins from otherBothropsvenoms. Bp-13 showed allosteric enzymatic behavior and maximal activity at pH 8.1, 36°–45°C. Full Bp-13 PLA2activity required Ca2+; its PLA2activity was inhibited by Mg2+, Mn2+, Sr2+, and Cd2+in the presence and absence of 1 mM Ca2+. In the mouse phrenic nerve-diaphragm (PND) preparation, the time for 50% paralysis was concentration-dependent (P<0.05). Both the replacement of Ca2+by Sr2+and temperature lowering (24°C) inhibited the Bp-13 PLA2-induced twitch-tension blockade. Bp-13 PLA2inhibited the contractile response to direct electrical stimulation in curarized mouse PND preparation corroborating its contracture effect. In biventer cervicis preparations, Bp-13 induced irreversible twitch-tension blockade and the KCl evoked contracture was partially, but significantly, inhibited (P>0.05). The main effect of this new Asp49 PLA2ofBothrops pauloensisvenom is on muscle fiber sarcolemma, with avian preparation being less responsive than rodent preparation. The study enhances biochemical and pharmacological characterization ofB. pauloensisvenom.

scholarly journals Biochemical, Pharmacological, and Structural Characterization of New Basic Bbil-TX fromBothriopsis bilineataSnake Venom

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Victor Corasolla Carregari ◽  
Rafael Stuani Floriano ◽  
Lea Rodrigues-Simioni ◽  
Flavia V. Winck ◽  
Paulo Aparecido Baldasso ◽  
...  
Keyword(s):  
Snake Venom ◽  
Protein Sequence ◽  
Maximal Activity ◽  
Optimal Conditions ◽  
High Identity ◽  
Phospholipid Hydrolysis ◽  
Rp Hplc ◽  
Crotalus Durissus ◽  
Didelphis Albiventris

Bbil-TX, a PLA2, was purified fromBothriopsis bilineatasnake venom after only one chromatographic step using RP-HPLC onμ-Bondapak C-18 column. A molecular mass of 14243.8 Da was confirmed by Q-Tof Ultima API ESI/MS (TOF MS mode) mass spectrometry. The partial protein sequence obtained was then submitted to BLASTp, with the search restricted to PLA2from snakes and shows high identity values when compared to other PLA2s. PLA2activity was presented in the presence of a synthetic substrate and showed a minimum sigmoidal behavior, reaching its maximal activity at pH 8.0 and 25–37∘C. Maximum PLA2activity required Ca2+and in the presence of Cd2+, Zn2+, Mn2+, and Mg2+it was reduced in the presence or absence of Ca2+. Crotapotin fromCrotalus durissus cascavellarattlesnake venom and antihemorrhagic factor DA2-II fromDidelphis albiventrisopossum sera under optimal conditions significantly inhibit the enzymatic activity. Bbil-TX induces myonecrosis in mice. The fraction does not show a significant cytotoxic activity in myotubes and myoblasts (C2C12). The inflammatory events induced in the serum of mice by Bbil-TX isolated fromBothriopsis bilineatasnake venom were investigated. An increase in vascular permeability and in the levels of TNF-a, IL-6, and IL-1 was was induced. Since Bbil-TX exerts a stronger proinflammatory effect, the phospholipid hydrolysis may be relevant for these phenomena.

scholarly journals Characterization of Streptococcus gordonii SecA2 as a Paralogue of SecA

2009 ◽  
Vol 191 (11) ◽  
pp. 3482-3491 ◽  
Author(s):  
Barbara A. Bensing ◽  
Paul M. Sullam
Keyword(s):  
Protein Transport ◽  
Maximal Activity ◽  
Biochemical Properties ◽  
Streptococcus Gordonii ◽  
Lower Solubility ◽  
Highly Sensitive ◽  
Sec System ◽  
High Degree

ABSTRACT The accessory Sec system of Streptococcus gordonii is essential for transport of the glycoprotein GspB to the bacterial cell surface. A key component of this dedicated transport system is SecA2. The SecA2 proteins of streptococci and staphylococci are paralogues of SecA and are presumed to have an analogous role in protein transport, but they may be specifically adapted for the transport of large, serine-rich glycoproteins. We used a combination of genetic and biochemical methods to assess whether the S. gordonii SecA2 functions similarly to SecA. Although mutational analyses demonstrated that conserved amino acids are essential for the function of SecA2, replacing such residues in one of two nucleotide binding folds had only minor effects on SecA2 function. SecA2-mediated transport is highly sensitive to azide, as is SecA-mediated transport. Comparison of the S. gordonii SecA and SecA2 proteins in vitro revealed that SecA2 can hydrolyze ATP at a rate similar to that of SecA and is comparably sensitive to azide but that the biochemical properties of these enzymes are subtly different. That is, SecA2 has a lower solubility in aqueous solutions and requires higher Mg2+ concentrations for maximal activity. In spite of the high degree of similarity between the S. gordonii paralogues, analysis of SecA-SecA2 chimeras indicates that the domains are not readily interchangeable. This suggests that specific, unique contacts between SecA2 and other components of the accessory Sec system may preclude cross-functioning with the canonical Sec system.

Prejunctional inhibitory muscarinic receptors on cholinergic nerves in human and guinea pig airways

1988 ◽  
Vol 64 (6) ◽  
pp. 2532-2537 ◽  
Author(s):  
P. A. Minette ◽  
P. J. Barnes
Keyword(s):  
Guinea Pig ◽  
Muscarinic Receptors ◽  
Contractile Response ◽  
Electrical Field Stimulation ◽  
Cholinergic Nerves ◽  
Ach Release ◽  
Pharmacological Characterization ◽  
Human Airways

We have investigated whether prejunctional inhibitory muscarinic receptors ("autoreceptors") exist on cholinergic nerves in human airways in vitro and whether guinea pig trachea provides a good model for further pharmacological characterization of these receptors. Pilocarpine was used as a selective agonist and gallamine as a selective antagonist of these autoreceptors. Acetylcholine (ACh) release from postganglionic cholinergic nerves was elicited by electrical field stimulation (EFS) (40 V, 0.5 ms, 32 Hz). In human bronchi, pilocarpine inhibited the contractile response to EFS in a dose-related fashion; the dose inhibiting 50% of the control contraction was 2.2 +/- 0.4 x 10(-7) (SE) M (n = 22), and the inhibition was 96% at 3 x 10(-5) M. The inhibitory effects of pilocarpine were antagonized by gallamine in a dose-related fashion. The results were qualitatively the same in the guinea pig. Gallamine significantly enhanced the contractile response to EFS in the guinea pig, whereas pirenzepine failed to do so, which suggests that M2-receptors are involved. We conclude that prejunctional muscarinic receptors that inhibit ACh release are present on cholinergic nerves in human airways and that guinea pig trachea is a good model for further pharmacological characterization of these receptors, which appear to belong to the M2-subtype.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

Pharmacological characterization of Tibouchina granulosa

Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
CC Guilhon ◽  
A Minho ◽  
AS Barros ◽  
PD Fernandes
Keyword(s):  
Pharmacological Characterization

Molecular and Pharmacological Characterization of Hamster HCA1 and HCA2

2016 ◽  
Vol 16 (1) ◽  
pp. 61-69
Author(s):  
Chester Kuei ◽  
Grace Lee ◽  
Victory Joseph ◽  
Jing Qian ◽  
Jingwen Yang ◽  
...  
Keyword(s):  
Pharmacological Characterization

C-Terminal amino acid sequence of chicken pepsinogen and its homology with sequences of other acid proteases

1980 ◽  
Vol 45 (4) ◽  
pp. 1144-1154 ◽  
Author(s):  
Miroslav Baudyš ◽  
Helena Keilová ◽  
Vladimír Kostka
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
The Other ◽  
Terminal Sequence ◽  
Terminal Part ◽  
Terminal Amino Acid ◽  
Tryptic Peptides ◽  
Terminal Amino ◽  
High Degree ◽  
Terminal Amino Acid Sequence

To determine the primary structure of the C-terminal part of the molecule of chicken pepsinogen the tryptic, chymotryptic and thermolytic digest of the protein were investigated and peptides derived from this region were sought. These peptides permitted the following 21-residue C-terminal sequence to be determined: ...Ile-Arg-Glu-Tyr-Tyr-Val-Ile-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ser-Pro-Leu-Ser.COOH. A comparison of this structure with the C-terminal sequential regions of the other acid proteases shows a high degree of homology between chicken pepsinogen and these proteases (e.g., the degree of homology with respect to hog pepsinogen and calf prochymosin is about 66%). Additional tryptic peptides, derived from the N-terminal part of the zymogen molecule whose amino acid sequence has been reported before, were also obtained in this study. This sequence was extended by two residues using an overlapping peptide. An ancillary result of this study was the isolation of tryptic peptides derived from other regions of the zymogen molecule.

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