TY - JOUR
TI - HB ARTA [BETA-45 (CD4) PHE-]CYS] - A NEW UNSTABLE HEMOGLOBIN WITH
REDUCED OXYGEN-AFFINITY IN TRANS WITH BETA-THALASSEMIA
AU - VASSILOPOULOS, G
AU - PAPASSOTIRIOU, I
AU - VOSKARIDOU, E and
AU - STAMOULAKATOU, A
AU - PREMETIS, E
AU - KISTER, J
AU - MARDEN, M and
AU - GRIFFON, N
AU - POYART, C
AU - WAJCMAN, H
AU - GALACTEROS, F and
AU - LOUKOPOULOS, D
JO - British Journal of Haematology
PY - 1995
VL - 91
TODO - 3
SP - 595-601
PB - Wiley
SN - 0007-1048, 1365-2141
TODO - 10.1111/j.1365-2141.1995.tb05353.x
TODO - HB VARIANT; UNSTABLE HB; LOW OXYGEN AFFINITY; BETA-DEGREES-THALASSEMIA
TODO - The interaction of rare Hb variants with beta degrees-thalassaemia
results in a quasihomozygous state where the erythrocytes contain the
variant as the only major adult Hb component, Such a situation is a
unique model that enables functional studies even in the case of a
neutral variant that could not be isolated from Hb A, We report here an
unusual patient carrying Hb Arta, a novel Hb variant [beta 45 (CD4)
Phe –> Cys], in trans with beta degrees-thalassaemia gene (beta degrees
39). The aminoacid substitution at the critical CD corner of this Hb
molecule renders the molecule unstable. In addition, haem is displaced
in a position that favours the deoxy (T) conformation of the variant,
but less than in Hb Cheverly [beta 45 (CD4) Phe –> Ser], and results
in a p50 of 43 mmHg (pH 7.4, 37 degrees C) in the red cells with
preservation of cooperativity. Solution studies of the almost pure Hb
Arta show a 50% decrease in oxygen affinity and normal cooperativity;
the Bohr effect and the interaction with organic phosphates are similar
to those of Hb A. Hb Arta retains both normal homo- and heterotropic
effects allowing a well-preserved oxygen transport in vivo despite a
mild anaemia.
ER -