SAMPLE ORIGIN SAMPLE PREP./SIZE PYROL. CONDITIONS TOTAL ION COUNTS
for amino acid composition, see Table 13; proinsulin-1ike components £ 1 ppm; total salts < 2%
Novo Res. Inst., Bagsvaerd, Denmark suspension in methanol; 10 yg standard
REMARKS - The pyrolysis pattern is dominated by fragments derived from the aromatic amino acids Phe and Tyr (m/z 92, toluene; m/z 94, phenol; m/z 108, cresol). The lack of Met residues explains the almost complete absence of a peak at m/z 48 (CH3SH+'). The minor peak at m/z 117 should be interpreted as phenylacetonitrile from Phe, as Trp residues (yielding indole at this mass value) are absent (ref. 46). The marked peak at m/z 76, tentatively assigned to CS2+" probably Involves the Cys-Cys-Cys tripeptide linkage region between the A and B chains.
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