Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-7-30
pubmed:databankReference
pubmed:abstractText
Functional and structural studies on hemoglobin and myoglobin from different animals and engineered variants have enlightened the great importance of the physico-chemical properties of the side-chains at topological position B10 and E7. These residues proved to be crucial to the discrimination and stabilisation of gaseous ligands. In view of the data obtained on the high oxygen affinity hemoglobin from Ascaris worms and a new mutant of sperm whale myoglobin, we selected the two mutations Leu B10-->Tyr and His E7-->Gln as potentially relevant to control ligand binding parameters in the alpha and beta-chains of human hemoglobin. Here, we present an investigation of three new mutants: HbalphaYQ (alpha2YQbeta2A), HbbetaYQ (alpha2Abeta2YQ) and HbalphabetaYQ (alpha2YQbeta2YQ). They are characterised by a very low reactivity for NO, O2 and CO, and a reduced cooperativity. Their functional properties are not inconsistent with the behaviour expected for a two-state allosteric model. Proteins with these substitutions may be considered as candidates for the synthesis of a possible "blood substitute", which should yield an O2 adduct stable to autoxidation and slowly reacting with NO. The mutant HbalphabetaYQ is particularly interesting because the rate of reaction of NO with the oxy and deoxy derivatives is reduced. A structural interpretation of our data is presented based on the 3D structure of deoxy HbalphabetaYQ determined by crystallography at 1.8 A resolution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
515-24
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10390349-Allosteric Regulation, pubmed-meshheading:10390349-Amino Acid Substitution, pubmed-meshheading:10390349-Binding Sites, pubmed-meshheading:10390349-Carbon Monoxide, pubmed-meshheading:10390349-Crystallization, pubmed-meshheading:10390349-Crystallography, X-Ray, pubmed-meshheading:10390349-Hemoglobins, pubmed-meshheading:10390349-Humans, pubmed-meshheading:10390349-Kinetics, pubmed-meshheading:10390349-Ligands, pubmed-meshheading:10390349-Models, Molecular, pubmed-meshheading:10390349-Molecular Sequence Data, pubmed-meshheading:10390349-Nitric Oxide, pubmed-meshheading:10390349-Oxidation-Reduction, pubmed-meshheading:10390349-Oxygen, pubmed-meshheading:10390349-Protein Engineering, pubmed-meshheading:10390349-Protein Structure, Secondary, pubmed-meshheading:10390349-Spectrum Analysis
pubmed:year
1999
pubmed:articleTitle
Modulation of ligand binding in engineered human hemoglobin distal pocket.
pubmed:affiliation
Department of Biochemical Sciences and C.N.R. Centre of Molecular Biology, University of Rome "La Sapienza", P.le A. Moro, 5, Rome, 00185, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't