Avtor/Urednik		Križaj, Igor; Bdolah, Avner; Gubenšek, Franc; Benčina, Petra; Pungerčar, Jože
Naslov		Protein and cDNA structures of an acidic phospholipase A2, the enzymatic part of an unusual, two-component toxin from Vipera palaestinae
Tip		članek
Vir		Biochem Biophys Res Commun
Vol. in št.		Letnik 227, št. 2
Leto izdaje		1996
Obseg		str. 374-9
Jezik		eng
Abstrakt		In the venom of Vipera palaestinae an unusual, two-component toxin was found. The two components of the toxin are an acidic phospholipase A2(VpaPLA2) and a basic protein, both with an apparent molecular mass of about 15 kDa. Each component alone is not toxic; however, their mixture is lethal. We have determined the amino acid and cDNA sequences of VpaPLA2. The protein primary structure was solved by sequencing the peptides generated by chemical cleavage of the molecule using CNBr, formic acid and hydroxylamine-hydrochloride and by enzymatic fragmentation with trypsin and chymotrypsin. VpaPLA2 consists of 122 amino acid residues and has all the structural characteristics of subgroup IIA PLA2s. It shows the highest amino acid similarity to a non-toxic phospholipase A2 from Eristocophis masmahoni (82%), whereas the most similar toxic phospholipases A2 share about 70% of residues with VpaPLA2. The substituion of His20 for a hydrophobic residue (Leu) in VpaPLA2 might be one of the reasons that its complex with the basic protein could not be observed.
Deskriptorji		PHOSPHOLIPASES A VIPER VENOMS DNA, COMPLEMENTARY AMINO ACID SEQUENCE BASE SEQUENCE DNA PRIMERS MOLECULAR SEQUENCE DATA PEPTIDE FRAGMENTS PEPTIDE MAPPING POLYMERASE CHAIN REACTION RECOMBINANT PROTEINS TRYPSIN VIPERIDAE