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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

PhTX-II a Basic Myotoxic Phospholipase A(2) from Porthidium hyoprora Snake Venom, Pharmacological Characterization and Amino Acid Sequence by Mass Spectrometry

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Author(s):
Huancahuire-Vega, Salomon [1, 2] ; Ponce-Soto, Luis Alberto [1] ; Marangoni, Sergio [1]
Total Authors: 3
Affiliation:
[1] State Univ Campinas UNICAMP, Inst Biol, Dept Biochem, BR-13083970 Campinas, SP - Brazil
[2] Union Peruvian Univ UPeU, Sch Med, Fac Hlth Sci, Dept Biochem & Pharmacol, Lima 15 - Peru
Total Affiliations: 2
Document type: Journal article
Source: TOXINS; v. 6, n. 11, p. 3077-3097, NOV 2014.
Web of Science Citations: 4
Abstract

A monomeric basic PLA(2) (PhTX-II) of 14149.08 Da molecular weight was purified to homogeneity from Porthidium hyoprora venom. Amino acid sequence by in tandem mass spectrometry revealed that PhTX-II belongs to Asp49 PLA(2) enzyme class and displays conserved domains as the catalytic network, Ca2+-binding loop and the hydrophobic channel of access to the catalytic site, reflected in the high catalytic activity displayed by the enzyme. Moreover, PhTX-II PLA(2) showed an allosteric behavior and its enzymatic activity was dependent on Ca2+. Examination of PhTX-II PLA(2) by CD spectroscopy indicated a high content of alpha-helical structures, similar to the known structure of secreted phospholipase IIA group suggesting a similar folding. PhTX-II PLA(2) causes neuromuscular blockade in avian neuromuscular preparations with a significant direct action on skeletal muscle function, as well as, induced local edema and myotoxicity, in mice. The treatment of PhTX-II by BPB resulted in complete loss of their catalytic activity that was accompanied by loss of their edematogenic effect. On the other hand, enzymatic activity of PhTX-II contributes to this neuromuscular blockade and local myotoxicity is dependent not only on enzymatic activity. These results show that PhTX-II is a myotoxic Asp49 PLA(2) that contributes with toxic actions caused by P. hyoprora venom. (AU)