Substance P as a transglutaminase substrate: identification of the reaction products by fast atom bombardment mass spectrometry.
Substance P was found to be an effective acyl donor substrate of transglutaminase in vitro, the reaction products having been examined by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fast atom bombardment mass spectrometry. Electrophoretic experiments showed that Substance P incorporated 14C-labeled polyamines when incubated with purified guinea pig liver transglutaminase and Ca2+. Extensive use of fast atom bombardment mass spectrometry allowed to establish that: i) a 1:1 adduct Substance P-spermine is formed; ii) only a single glutamine residue out of two, i.e. Gln-5, acts as acyl donor, iii) the single lysine residue of the neuropeptide is unable to act as acyl acceptor. A direct analytical methodology to detect transglutaminase reaction products is described.
Porta
R
R
Dipartimento di Biochimica e Biofisica, Universita di Napoli, Italy.
Esposito
C
C
Metafora
S
S
Pucci
P
P
Malorni
A
A
Marino
G
G
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005973:Glutamine / Q000378:metabolism; D006168:Guinea Pigs; D013058:Mass Spectrometry; D013373:Substance P / Q000378:metabolism*; D011503:Transglutaminases / Q000032:analysis / Q000378:metabolism*
D005973:Glutamine; D013373:Substance P; D011503:Transglutaminases