| Autor: |
Srinivasa BR, Carpenter FH |
| Jazyk: |
angličtina |
| Zdroj: |
International journal of peptide and protein research [Int J Pept Protein Res] 1983 Aug; Vol. 22 (2), pp. 214-22. |
| DOI: |
10.1111/j.1399-3011.1983.tb02088.x |
| Abstrakt: |
The bifunctional reagents, oxalyl-(Met-ONp)2 and malonyl-(Met-ONp)2 have been prepared and investigated as reversible cross-linking reagents for insulin and model compounds. The removal of the cross-linking residues was demonstrated by the cyanogen bromide cleavage of oxalyl-(Met-Phe-OMe)2 and malonyl-(Met-Phe-OMe)2. Zinc-insulin reacted with a molar equivalent of oxalyl-(Met-ONp)2 or malonyl-(Met-ONp)2 in presence of excess triethylamine to yield oxalyl-(Met)2-insulin and malonyl-(Met)2-insulin, respectively. In these derivatives the N-terminal phenylalanine (B1 residue) was free. Thus the cross-link was between A1 and B29 residues in insulin. All three disulfide bonds of these insulin derivatives undergo reduction with tributylphosphine to give six sulfhydryls. Air-oxidation of reduced oxalyl-(Met)2-insulin and malonyl-(Met)2-insulin in 0.05 M disodium phosphate, pH 9.5, yielded products which were indistinguishable from oxalyl-(Met)2-insulin and malonyl-(Met)2-insulin respectively, as measured by physicochemical and biological methods. Cyanogen bromide cleavage of reduced and reoxidized malonyl-(Met)2-insulin in 70% formic acid regenerated insulin quantitatively, but only 40% of insulin was determined from similar treatment of oxalyl-(Met)2-insulin. The regenerated insulins exhibited the biological activity of native insulin. These studies strongly suggest that disulfide bonds formed during oxidation of reduced oxalyl-(Met)2-insulin and malonyl-(Met)2-insulin are identical to those found in insulin. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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