ISSN:
1573-3904
Keywords:
Matrix-assisted laser desorption ionization
;
Fluorogenic substrates
;
Photochemistry
;
Nitrosobenzyl moiety
;
Photodeoxygenation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary By means of MALDI-TOF analysis of peptides containing a nitrobenzyl moiety, we have observed that the predominant signal often corresponds to ions that have eliminated multiple oxygen atoms, [M−On+H]+, and not to the protonated molecular ion, [M+H]+. Matrix selection for handling these types of molecules appears to be important. The MALDI-TOF matrices, such as sinapinic acid (3,5-dimethoxy-4-hydroxycinnamic acid) and α-cyano-4-hydroxycinnamic acid, resulted in the appearance of significant levels of the photodeoxygenated species, whereas 4-hydroxyazobenzene-2-carboxylic acid appeared to moderately and in some cases completely suppress the photodeoxygenation reaction. This phenomenon was independent of laser intensity. Photodeoxygenation was not observed with electrospray or fast atom bombardment ionization techniques. Therefore, use of MALDI should be avoided with peptides containing a nitrobenzyl moiety and similar moieties that are prone to reactive photochemistry.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00142243
