FAST ATOM BOMBARDMENT MASS SPECTROMETRY (FABMS) ANALYSIS OF AN N- TERMINAL - BLOCKED PEPTIDE
FABMS analysis of T-lb peptide before and after one cycle of Edman degradation indicated an unblocked N-terminal Thr residue for this tryptic peptide. In contrast , our data showed a molecular protonated ion, MH + for T- la peptide at 655 mass units (mu) which is 42 mu higher than the MH ion of T-...
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| Format: | Article |
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| Language: | English |
| Published: |
University of Tehran
1992-06-01
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| Series: | Journal of Sciences, Islamic Republic of Iran |
| Online Access: | https://jsciences.ut.ac.ir/article_31200_331f7b41e33370ddae16190f0f100677.pdf |
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| Summary: | FABMS analysis of T-lb peptide before and after one cycle of Edman
degradation indicated an unblocked N-terminal Thr residue for this tryptic peptide.
In contrast , our data showed a molecular protonated ion, MH + for T- la peptide at
655 mass units (mu) which is 42 mu higher than the MH ion of T- 1b peptide. In
addition, T- la peptide was not amenable to one cycle of manual Edman degradation.
These observations suggest that the N-terminal residue of T- 1 a peptide is blocked by
a chemical group having a mass of 42 mu. This observation is consistent with the
presence of an N-terminal acetyl group. This prediction was further investigated by
complete characterization of the gas phased fragment ions, originated from the
individual peptides, using link-scanning approach. The fragment ions again suggest
an acetyl group attached to an N-terminal threonine. In addition, the fragment ions
provide evidence that the two peptides (T-la and T-lb) have identical structures
except for the N-acetyl group |
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| ISSN: | 1016-1104 2345-6914 |