Structural and crystallographic observations on hagfish insulin.

摘要: INSULIN is a well defined globular protein made up of two small peptide chains linked together through disulphide bonds1,2. It contains an unusually high proportion hydrophobic residues and thus tends to readily self-associate3,4. In many species the hormone forms dimers in solution and, presence Zn2,4ions, hexamers4,5. Recently, Hodgkin coworkers6,7 have determined crystal structure rhombohedral form porcine Zn-insulin at 1.9 A resolution6,7. Two molecules insulin occur asymmetric unit, related approximate twofold axis nearly symmetrical dimer. Three such turn associate coordination histidine B10 with zinc ions spherical hexamer. spite availability amino acid sequences wide variety vertebrate insulins2,8, however, comparative studies on detailed modes association insulins been lacking.