Determination of the disulfide bond pattern of a novel C-type lectin from snake venom by mass spectrometry

The disulfide bond pattern of Trimeresurus stejnegeri lectin (TSL), a new m ember of the C-type lectin family, was determined by mass spectrometry. Fou r intrachain disulfide bonds of TSL, Cys(3)-Cys(14), Cys(31)-Cys(131), Cys( 38)-Cys(133) and Cys(106)-Cys(123), and two interchain linkages, Cys(2)-Cys (2) and Cys(86)-Cys(86), were determined. Three strategies were used in thi s work. One intrachain (Cys(106)-Cys(123)) and one interchain (Cys(86)-Cys( 86)) disulfide linkages were detected by standard MS methods. The disulfide bonds Cys(2)-Cys(2) and Cys(3)-Cys(14) were analyzed using a modified part ial reduction procedure and MS/MS. The last two disulfide bonds were charac terized by a MS/MS/MS technique. The strategies developed in this work coul d be applied more generally to detection of disulfide bond patterns. Copyri ght (C) 2001 John Wiley & Sons, Ltd.