@article{2a43c39a68b24882bc0cb04b93a7be4d,
title = "Site-directed mutagenesis in hemoglobin. Effect of some mutations at protein interfaces",
abstract = "The role of selected amino acid residues in the monomer-monomer contacts of Hb A has been studied by site-directed mutagenesis of the α chain bearing substitutions in the subunit surfaces. Mutation α 38Thr → Trp induced a stabilization of tetrameric Hb-CO with a decrease of the Kd for the equilibrium α2β2 ⇌ 2αβ, but had no effect on ligand binding. Mutation α40Thr→Arg resulted in a complete loss of cooperativity in ligand binding. Mutation α103His→Val had no noticeable effect. We also studied the behaviour of isolated, mutated α chains with respect to self association: compared to wt α chains, mutant α38Thr→Trp showed stabilization of the dimeric state and (at high protein concentration) a detectable amount of tetramers. Mutant α103His→Val showed only a minor stabilization of the α2 dimer.",
keywords = "Hemoglobin mutant, Protein engineering, Subunit contact",
author = "B. Vallone and P. Vecchini and V. Cavalli and M. Brunori",
note = "Funding Information: A~~~izo~~lctl~Ween wleisrhlr tso gratefully acknowledge K. Nagdi and N.H. Komtyama (LMB-MRC, Cambridge, LrK) for their Invaluable help m the productton of Hb mutants, mittally carried out at LMB-MRC. We also thank C. Chothta and A.M Lesk (ibtdem) for their stimulating suggestions and A. Bellelli, R Ippoliti. E Lendaro and A. Brancaccto (Rome) for their help in some hemoglobin mampulattons We are very grateful to Prof. M Tomasi and Mr. B. Volpi of ISS for their help m optimizmg bacterial growth conditions. Permission to use the Hb expression system m E co/r for scienttc purposes given by Somatogen Inc. ts gratefully acknowledged. B.V. was supported by an EMBO short term fellowship and by the Societa Itahana di Btocht-mica. Grants from the MURST (40% Liveprotein) and the CNR (Progetto Strategic0 {\textquoteleft}Trasduztone{\textquoteright}) are gratefully ackoaledged.",
year = "1993",
month = jun,
day = "14",
doi = "10.1016/0014-5793(93)81375-A",
language = "English",
volume = "324",
pages = "117--122",
journal = "FEBS Letters",
issn = "0014-5793",
number = "2",
}