Τίτλος:
HB ARTA [BETA-45 (CD4) PHE-]CYS] - A NEW UNSTABLE HEMOGLOBIN WITH
REDUCED OXYGEN-AFFINITY IN TRANS WITH BETA-THALASSEMIA
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
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.
Συγγραφείς:
VASSILOPOULOS, G
PAPASSOTIRIOU, I
VOSKARIDOU, E and
STAMOULAKATOU, A
PREMETIS, E
KISTER, J
MARDEN, M and
GRIFFON, N
POYART, C
WAJCMAN, H
GALACTEROS, F and
LOUKOPOULOS, D
Περιοδικό:
British Journal of Haematology
Λέξεις-κλειδιά:
HB VARIANT; UNSTABLE HB; LOW OXYGEN AFFINITY; BETA-DEGREES-THALASSEMIA
DOI:
10.1111/j.1365-2141.1995.tb05353.x
