Synthesis and Biological Properties of Insulin-Deoxycholic Acid Chemical Conjugates

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• 作者：Seulki Lee ; Kwangmeyung Kim ; Tadiparthi Suresh Kumar ; Jisook Lee ; Sang Kyoon Kim ; Dong Yun Lee ; Yong-kyu Lee ; and Youngro Byun
• 刊名：Bioconjugate Chemistry
• 出版年：2005
• 出版时间：May 2005
• 年：2005
• 卷：16
• 期：3
• 页码：615 - 620
• 全文大小：109K
• 年卷期：v.16,no.3(May 2005)
• ISSN：1520-4812

文摘

Bile acids have been considered very useful in the preparation of new pharmaceuticals, and morerecently in the preparation of peptide and protein drugs because of their natural chemical and biologicalproperties. In this study, we modified recombinant human insulin by covalently attaching deoxycholicacid (DOCA) derivatives in order to synthesize orally active insulin analogues. DOCA derivatives,namely succinimido deoxycholate and succinimido bisdeoxycholyl-L-lysine were prepared and sitespecifically conjugated at Lys^B29 of insulin. The resultant insulin conjugates, [N^B29-deoxycholyl] insulin(Ins-DOCA) and [N^B29-bisdeoxycholyl-L-lysil] insulin (Ins-bisDOCA), were studied for their chemical,structural, and biological properties. Their chemical properties were determined by HPLC, MALDI-TOF mass spectroscopy, and dynamic light scattering. Lipophilicity and self-aggregation behavior ofinsulin conjugates were enhanced with increasing number of labeled bile acid. The far-ultravioletregion of circular dichroism spectra showed no significant change of the tertiary structure of insulinin aqueous solution due to conjugation. Competitive insulin binding assay with HepG2 cells revealedthat monosubstituted insulin conjugates still retained high binding affinity to the insulin receptor.When the insulin conjugates were intravenously administered (0.33 IU/kg) to streptozotocin (STZ)-induced diabetic rats, the conjugates showed sustained biological activity for a longer period with thesimilar lowest blood glucose level (glucose nadir), compared to native insulin. In further studies, theresulting new insulin conjugates will be investigated for their oral efficiency as a long-acting insulinformulation for the treatment of diabetic patients.