Analysis of proteins from snake venom of Malayan Krait Bungarus candidus

Abstract

This research involves analysis of proteins from Bungarus candidus venom. Firstly , the mixture proleins were separated using gel electrophoresis and ion exchange chromatography. After that, the separated proteins were analyzed by mass spectrometry; matrix assisted laser desorption ionization mass spectrometry (MALDI- MS) and electrospray ionization mass spectrometry (ESI-MS). There are 17 and 36 spots in silver stained gel and coomassie blue stained gel, respectively. From peptide mass mapping, the searching results cannot confirm the identity of proteins. The results from the separation of proteins by using ion exchange chromatography, one protein called "prote in A" with molecular weight of 7453 Da was found in fraction No, 6 and one protein called "protein B" which has molecular weight of 6670 Da was found in fraction No. 8. The N-terminal sequencing result of protein A has found 11 residues which is KTKI_PEKD_OKV and the N-terminal sequencing of protein B was NLINFMEMIRYT. From the result of peptide mass mapping shows that protein A is candoxin. Furthermore, the tryptic peptide and chymotrytic peptide fragments of protein A were sequenced by ESI-0-TOF. The amino acid sequences of four peptides are VCASGEK, YCFKESWR, EARGTR and CCTTDDCN, which are similar to the eighteenth to thirty eighth amino acids residues from N-terminal of candoxin. However, the result of N- terminal sequences and the molecular weight was not matched with candoxin. Consequently, it might be a new protein. Therefore, further analysis of this protein was required. Protein B from fraction No.8 cannot be analyzed according to purity.