Mass spectrometric analysis of rArtinM. A) Molecular mass of rArtinM (of 16099.5 Da) was determined by ESI-triple quadrupole mass spectrometer. The insertion in figure shows protonated envelop of ions which were de-convoluted to Mw using MaxEnt 1 algorithm. B) Mass fingerprint obtained from tryptic digested rArtinM in solution was analyzed by ESI-triple quadrupole scanning from 400 to 1500 amu in the positive ion mode for detection of protonated peptides. C) Each tryptic peptide was subjected to collision-induced dissociation to produce a fragment ion pattern and the amino acid sequence was deduced from fragment ions type b and y, as an example, spectrum of tryptic peptide m/z 713.7 [M + 2 H+] which corresponds to the C-terminal peptide. Other tryptic peptides are listed in Table 1. D) Amino acid sequence of rArtinM determined by Edman degradation (N-terminal, residues 1–20) and tryptic peptides by mass spectrometry (bold).