Amino acid sequence of bovine gamma E (IVa) lens crystallin

✍ Scribed by Greg W. Kilby; Margaret M. Sheil; Denis Shaw; John J. Harding; Roger J. W. Truscott

• Publisher: Cold Spring Harbor Laboratory Press
• Year: 2008
• Tongue: English
• Weight: 401 KB
• Volume: 6
• Category: Article
• ISSN: 0961-8368
• DOI: 10.1002/pro.5560060418

✦ Synopsis

Abstract

When electrospray ionization mass spectrometry (ES‐MS) was used to analyze purified bovine gamma E (γIV~a~)‐crystallin, it yielded a relative molecular mass (M~r~) of 20,955 ± 5. This mass is significantly different from that calculated from the published sequence (M~r~ 20,894) (White HE et al., 1989, J Mol Biol 207:217–235). Further, ES‐MS analysis of the protein after it had been reduced and carboxymethylated indicated the presence of five cysteine residues, whereas the published sequence contains six (Kilby GW et al., 1995, Eur Mass Spectrom 1:203–208). The entire protein sequence of γE crystallin has therefore been studied via a combination of ES‐MS, ES‐MS/MS, and Edman amino acid sequencing. The corrected sequence gives an M~r~ of 20,955.3, which matches that obtained by ES‐MS analysis of the purified native protein. The corrected sequence is also in agreement with a recent cDNA sequence obtained for a bovine γ‐crystallin by R. Hay (pers. comm.).