Open AccessHemoglobin Saint Mandé [β102 (G4) Asn→Tyr]
Author(s) -
POYART Claude,
SCHAAD Olivier,
KISTER Jean,
GALACTEROS Frédéric,
EDELSTEIN Stuart J.,
BLOUQUIT Yves,
AROUS Nicole
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb15624.x
Subject(s) - bohr effect , chemistry , cooperativity , hemoglobin , mand , hydrogen bond , chloride , oxygen , stereochemistry , molecule , biochemistry , organic chemistry , oxygen–haemoglobin dissociation curve , psychology , developmental psychology , autism
Oxygen equilibrium studies of purified hemoglobin Saint Mandé (Hb SM) [β102 (G4) Asn→Tyr] reveal a decreased oxygen affinity and cooperativity but to a lesser extent than found for Hb Kansas (β102 Thr). The low affinity of Hb SM depends on environmental conditions: eliminating chloride or raising the pH greatly elevated the ratio of p 50 of Hb SM to that of Hb A. The alkaline Bohr effect is reduced by about 40%. The effects of anions (chloride, organophosphates) binding to deoxy Hb SM are also reduced. These data indicate that the functional properties of Hb SM are intermediary between Hb A and Hb Kansas. In addition, molecular graphics modeling of Hb SM in the oxy and deoxy structures indicate the possibility of a new hydrogen bond in the T state between β 1 102 Tyr and α 2 42 Tyr. Stabilisation of the T state in this manner is a plausible explanation for several of the effects observed.