Identification by fast atom bombardment mass spectrometry of insulin fragments produced by insulin proteinase.
We describe the isolation by reversed-phase h.p.l.c. of a number of products of the degradation of insulin by insulin proteinase and their direct analysis by fast atom bombardment mass spectrometry (f.a.b.-m.s.). Various semisynthetically labelled insulins were used, including [[2H2]GlyA1]insulin and [18O]LysB29]insulin. The results obtained confirm and extend the results obtained by non-mass-spectrometric methods [Davies, Muir, Rose & Offord (1988) Biochem. J. 249, 209-214, and papers cited therein]. Cleavage sites were identified between positions A13-A14, A14-A15, B9-B10, B13-B14, B24-B25 and B25-B26. The advantages and disadvantages of the application of f.a.b.-m.s. to such studies are discussed.
Savoy
L A
LA
Département de Biochimie Médicale, Centre Médical Universitaire, Geneva, Switzerland.
Jones
R M
RM
Pochon
S
S
Davies
J G
JG
Muir
A V
AV
Offord
R E
RE
Rose
K
K
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D007328:Insulin / Q000031:analogs & derivatives*; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000032:analysis*
D007328:Insulin; D010446:Peptide Fragments