MALDI-MS analysis of peptides modified with photolabile arylazido groups.
The ability of MALDI-MS to analyze photolabile arylazido peptide derivatives was investigated. Peptides containing UV-labile p-azidobenzoyl groups were subjected to MALDI-MS analysis in a variety of matrices. As standard MALDI-MS employs a UV laser (337 nm), we investigated conditions that would allow detection of the intact molecule ions for these light-sensitive peptides. When using alpha-cyano-4-hydroxycinnamic acid (ACHC) or 2,5 dihydroxybenzoic acid (DHB) as the matrix, photoinduced degradation products were prevalent. In contrast, when employing the matrix sinapinic acid, the intact molecule ion corresponding with the azido peptide was the predominant signal. The protection of photolabile azido derivatives correlates with the UV absorbance properties of the matrix employed, i.e., sinapinic acid, which exhibits a strong absorbance near 337 nm, most efficiently protects the azido derivative from photodegradation.
The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA.
William
W
Low
James
J
Kang
Michael
M
DiGruccio
Dean
D
Kirby
Marilyn
M
Perrin
Wolfgang H
WH
Fischer
D001386:Azides / Q000737:chemistry*; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D010777:Photochemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D001386:Azides; D010446:Peptide Fragments; D010455:Peptides; C104416:astressin; D003346:Corticotropin-Releasing Hormone