The observation of quasi-molecular ions from a tiger snake venom component (Mr 13 309) using 252Cf-plasma desorption mass spectrometry

Abstract A method involving fast heavy-ion bombardment of a solid sample called 252 Cf-plasma desorption mass spectrometry has been used to study of a non-enzymatic, non-toxic phospholipase homolog from Australian tiger snake ( Notechis scutatus ) venom. The protein consists of 119 amino acids in a single polypeptide chain cross-linked by 7 disulfide bridges. The isotopically averaged molecular mass as determined by protein sequence analysis is 13 309 atomic mass units (amu). The mass distributions were studied by means of time-of-flight measurements. Quasi-molecular ions associated to the molecule and its dimer were observed. The mass of the quasi-molecular ion corresponding to the molecule was determined to be 13 285 ± 25 amu.