ISSN:
1744-313X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The product of the A blood group gene in the erythrocyte membrane and serum from ‘weak A’ variants was investigated using low and high molecular weight acceptors and compared with common A1 and A2 blood samples. A reduced enzyme activity was detected, but only in some of the A variants, namely the A3 (eight out of eleven), Am or Ay samples. Other sera from A3 (three out of eleven), Ax, Aend or Ael individuals were apparently devoid of enzyme activity.A kinetic study by temperature inactivation of A blood group sera also showed that A enzymes are more labile than B enzymes from BI or BII sera. Moreover, in one case (A3 sample Del.), a very fast inactivation of the A enzyme was observed, suggesting the occurrence of a variant enzyme qualitatively different from the others so far studied.The erythrocyte membrane preparations from all A variants contained no detectable A enzyme activity except for the A1 and A2 samples, the former being three to five times more active than the latter. The B enzyme activities from four samples of B RBC tested were comparatively stronger than the A enzyme activity of A1 RBC.The results were discussed and it was suggested that the synthesis and/or the secretion of the A enzyme in the organism is not uniform from one tissue to another, but could depend on which of the ‘weak A’ alleles or modifier genes is involved.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1744-313X.1978.tb00635.x
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