Cosmatos A, Ferderigos N, Katsoyannis PG. Chemical synthesis of [des(tetrapeptide B27--30), Tyr(NH2)26-B] and [des(pentapeptide B26--30), Phe(NH2)25-B] bovine insulins.
INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 2009;
14:457-71. [PMID:
395118 DOI:
10.1111/j.1399-3011.1979.tb01957.x]
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Abstract
Two analogs of bovine insulin, [des(tetrapeptide B27--30), Tyr(NH2)26-B] and [des(pentapeptide B26--30), Phe(NH2)25-B] insulin, which differ from the parent molecule in that the C-terminal tetrapeptide and pentapeptide sequences, respectively, from the B chain have been eliminated and the newly exposed residues are amidated, have been synthesized. The [des(tetrapeptide B27--30), Tyr(NH2)26-B] insulin shows potencies of 16.8 IU/mg by the mouse convulsion assay method and 10.8 IU/mg by the radioimmunoassay method. The [des(pentapeptide B26--30), Phe(NH2)25-B] insulin possesses a potency of 10.5 IU/mg when assayed by the mouse convulsion method and 14 IU/mg by the radioimmunoassay technique. The potencies of these analogs are higher than the potencies of the respective non-amidated derivatives (Katsoyannis et al., 1973, 1974). It is speculated that the gradual decline of biological activity observed as amino acid residues are eliminated from the C-terminal region of the B chain of insulin is due to the proximity of a hydrophilic carboxyl group to the hydrophobic core of the protein molecule.
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