1bij
From Proteopedia
CROSSLINKED, DEOXY HUMAN HEMOGLOBIN A
Overview
The crystal structure of human hemoglobin crosslinked between the Lysbeta82 residues has been determined at 2.30 A resolution. The crosslinking reaction was performed under oxy conditions using bis(3, 5-dibromosalicyl) fumarate; the modified hemoglobin has increased oxygen affinity and lacks cooperativity. Since the crystallization occurred under deoxy conditions, the resulting structure displays conformational characteristics of both the (oxy) R and the (deoxy) T-states. beta82XLHbA does not fully reach its T-state conformation due to the presence of the crosslink. The R-state-like characteristics of deoxy beta82XLHbA include the position of the distal Hisbeta63 (E7) residue, indicating a possible reason for the high oxygen affinity of this derivative. Other areas of the molecule, particularly those thought to be important in the allosteric transition, such as Tyrbeta145 (HC2) and the switch region involving Proalpha(1)44 (CD2), Thralpha(1)41 (C6) and Hisbeta(2)97 (FG4), are in intermediate positions between the R and T-states. Thus, the structure may represent a stabilized intermediate in the allosteric transition of hemoglobin.
About this Structure
1BIJ is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of Lysbeta(1)82-Lysbeta(2)82 crosslinked hemoglobin: a possible allosteric intermediate., Fernandez EJ, Abad-Zapatero C, Olsen KW, J Mol Biol. 2000 Mar 10;296(5):1245-56. PMID:10698631 Page seeded by OCA on Fri May 2 11:33:22 2008
