1dei

Publication Abstract from PubMed

The crystal structure of desheptapeptide (B24-B30) insulin (DHPI), a virtually inactive analog of insulin, was determined at 1.6 A resolution. In the refined structure model, DHPI retains three alpha-helices (A1-A8, A12-A18, and B9-B19) as its structural framework, while great conformational changes occur in the N and C termini of B-chain. The beta-turn, which lies in B20-B30 in insulin and insulin analogs with high potency, no longer exists in DHPI. Relative motion is observed among the three alpha-helices, each as a rigid functional group. In contrast, a region covering B5-B6 and A6-A11 exhibits a relatively stable conformation. We interpret our results as identifying: (i) the importance of beta-turn in determining the receptor-binding potency of insulin and (ii) a leading role of PheB24 in maintaining the beta-turn structure.

Crystal structure of desheptapeptide(B24-B30)insulin at 1.6 A resolution: implications for receptor binding.,Bao SJ, Xie DL, Zhang JP, Chang WR, Liang DC Proc Natl Acad Sci U S A. 1997 Apr 1;94(7):2975-80. PMID:9096331^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.