Purification, properties, and amino acid sequence of a hemoglobinuria-inducing phospholipase A(2), MiPLA-1, from Micropechis ikaheka venom

Citation
R. Gao et al., Purification, properties, and amino acid sequence of a hemoglobinuria-inducing phospholipase A(2), MiPLA-1, from Micropechis ikaheka venom, ARCH BIOCH, 369(1), 1999, pp. 181-192
Citations number
62
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
ISSN journal
0003-9861 → ACNP
Volume
369
Issue
1
Year of publication
1999
Pages
181 - 192
Database
ISI
SICI code
0003-9861(19990901)369:1<181:PPAAAS>2.0.ZU;2-6
Abstract
Dark-colored urine is one of the clinical symptoms of envenomation by Micro pechis ikaheka (New Guinea small-eyed snake). We have purified a phospholip ase A(2), MiPLA-1, which induces dark-colored urine in experimental mice, t o homogeneity. The analysis of the dark-colored urine by electrophoresis an d N-terminal sequence determination indicated that the color of mouse urine is due to hemoglobin in the urine but not myoglobin. MiPLA-1 is the first hemoglobinuria-inducing toxin. Insignificant hemolytic activity of MiPLA-1 indicates that hemoglobinuria is not due to lysis of erythrocytes by MiPLA- 1. This suggests that hemoglobinuria induced by MiPLA-1 may be due to kidne y leakage caused by unknown mechanisms. MiPLA-1 also showed other biologica l effects, including myotoxicity as well as anticoagulant and antiplatelet effects, Structural studies show that MiPLA-1 is a basic protein with a mol ecular mass of 14041.60 +/- 1.78 as determined by electrospray mass spectro metry. We have determined the complete amino acid sequence of MiPLA-1. It i s a 124-amino-acid protein with a "pancreatic loop" and belongs to group IB phospholipase A(2) enzymes. Two short segments banked by proline brackets are found in the sequence of MiPLA-1. These segments are on the surface of the molecule and hence may be involved in protein-protein recognition. (C) 1999 Academic Press.