PMID: 18977386

Authors:

Sreekanth R, Pattabhi V, Rajan SS

Title:

Metal induced structural changes observed in hexameric insulin.

Journal:

Int J Biol Macromol. 2009 Jan 1;44(1):29-36. Epub 2008 Oct 14.

Abstract:

The metal ions in insulin hexamer play a crucial role in the T to R conformational transitions. We have determined the crystal structures of 2Mn2+, 1Rb1+ and 4Ni2+ human arg-insulin and compared them with the 2Zn2+ structure. The first two structures exist in the T3R3f state like the native 2Zn2+ arg-insulin, while the 4Ni2+ adopts a T6 conformation. The metal coordination is found to be tetrahedral in all the structures except that of nickel where a dual octahedral and tetrahedral coordination is found at one site. Rubidium occupies only one of the high affinity metal binding sites. The metal induced structural changes observed, have been explained.