ISSN:
0887-3585
Keywords:
X-ray diffraction
;
allosterism
;
zinc/phenol interaction
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Hexameric insulin has been crystallized from different conditions ina variety of crystalline modifications. In the presence of ∼1%phenol and at a pH of 8.5, a new rhom-bohedral form is produced, space group R3, a = 79.92 Åand c = 40.39 Å, in whichthe asymmetric unit consists of a dimer. The structur has been solved and refined, using data between 8.0 and 2.5 Å resolution, to a residual of0.157. The two monomers in the asymmetric unit have nearly identical R conformations, that is, residues Bl through B8 are α-helical, producing a continuous α-helix from Bl through B19. A phenol molecule is hydrogen bonded to the carbonyl oxygen of A6 Cys of each monomer. Small differences in conformation and the final (2Fo-Fc) and difference electron density maps suggest that an additional phenol molecule is coordinated to one of the two zinc ions.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prot.340140309
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