The amino acid sequence of phospholipase A, fractions DE-I and DE-II

The complete amino acid sequences of phospholipase A (Fractions DE-I and DE-II) from Naja melanoleuca (Forest cobra) have been elucidated. The reduced and S-carboxymethylated isoenzyme were digested with trypsin and thermolysin and the peptides were purified by ion-exchange chromatography, gel filtration and chromatography or electrophoresis on paper. The Edman procedure, either through the use of the automatic sequencer or by manual manipulation, was employed to obtain the sequences of the intact isoenzymes and the pure peptidesmthe thermolysin digest provided the necessary overlapping peptides which allowed the alignment of the tryptic peptides of Fraction DE-I. The tryptic peptides of Fraction DE-II were either identical or homologous to the tryptic peptides of Fraction I and Fraction III [12] and were aligned in the same order as that of Fractions DE-I or DE-III. The amino acid sequence of N. melanoleuca phospholipase A, Fraction I, shows a high degree of homology with Fraction DE-II and also with Fraction DE-III, previously reported on [12].