1gli › Citations

Probing the alpha 1 beta 2 interface of human hemoglobin by mutagenesis. Role of the FG-C contact regions.

Vallone B, Bellelli A, Miele AE, Brunori M, Fermi G
J Biol Chem 271 12472-80 (1996)
Cited: 4 times
EuropePMC logo PMID: 8647854

Abstract

The allosteric transition of hemoglobin involves an extensive reorganization of the alpha 1 beta 2 interface, in which two contact regions have been identified. This paper concerns at the effect of two mutations located in the "switch" (alpha C3 Thr --> Trp) and the "flexible joint" (beta C3 Trp --> Thr). We have expressed and characterized one double and two single mutants: Hb alpha T38W/beta W37T, Hb beta W37T, and Hb alpha T38W, whose structure has been determined by crystallography. We present data on: (i) the interface structure in the contact regions, (ii) oxygen and CO binding kinetics and cooperativity, (iii) dissociation rates of deoxy tetramers and association rates of deoxy dimers, and (iv) the effect of NaI on deoxy tetramer dissociation rate constant. All the mutants are tetrameric and T-state in the deoxygenated derivative. Reassociation of deoxygenated dimers is not modified by interface mutations. DeoxyHb alpha T38W/beta W37T dissociate much faster. We propose a binding site for I- at the switch region. The single mutants binds O2 cooperatively; the double one is almost non-cooperative, a feature confirmed by CO binding. The functional data, analyzed with the two-state model, indicate that these mutations reduce the value of the allosteric constant LO.

Reviews - 1gli mentioned but not cited (2)

  1. An overview of the structures of protein-DNA complexes. Luscombe NM, Austin SE, Berman HM, Thornton JM. Genome Biol 1 REVIEWS001 (2000)
  2. The role of globins in cardiovascular physiology. Keller TCS, Lechauve C, Keller AS, Brooks S, Weiss MJ, Columbus L, Ackerman H, Cortese-Krott MM, Isakson BE. Physiol Rev 102 859-892 (2022)


Articles citing this publication (2)

  1. Studies of the interaction between paraquat and bovine hemoglobin. Wang YQ, Zhang HM, Zhang GC, Liu SX, Zhou QH, Fei ZH, Liu ZT. Int J Biol Macromol 41 243-250 (2007)
  2. Allosteric free energy changes at the alpha 1 beta 2 interface of human hemoglobin probed by proton exchange of Trp beta 37. Mihailescu MR, Fronticelli C, Russu IM. Proteins 44 73-78 (2001)


Quick links