[Changes of protein tyrosine phosphorylation in erythrocyte band 3 glucose-6-phosphate dehydrogenase deficiency].
OBJECTIVE
To explore the hemolytic mechanism of glucose-6-phosphate dehydrogenase (G6PD) deficient erythrocytes in the view of phosphorylation of membrane protein.


METHODS
The alternation of membrane protein phosphorylation and the effect of dithiothreitol (DTT) on protein phosphorylation were analysed by Western blot technique. The activity of phosphotyrosine phosphatase (PTPs) was determined by using p-nitrophenyl phosphate as substrate.


RESULTS
Tyrosine phosphorylation of band 3 protein was obviously enhanced in G6PD-deficient erythrocytes. The activity of PTPs was low compared to the normal erythrocytes. The level of phosphotyrosine in G6PD-deficient erythrocytes incubated with DTT was almost the same as in those without DTT. The results were consistent with the activity of PTPs.


CONCLUSIONS
PTPs activity reduction and tyrosine phosphorylation enhancement induced by oxidation in G6PD deficiency play an important role in erythrocytes hemolysis. However, the alternation of thiol group is not the only factor affecting the activity of PTPs in G6PD-deficient erythrocytes.
Yu
Guoyu
G
Department of Biochemistry, Kunming Medical College, Kunming 650031, China.
Li
Jialin
J
Tian
Xingya
X
Lin
Hong
H
Wang
Xiaoying
X
D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism*; D015153:Blotting, Western; D004910:Erythrocyte Membrane / Q000378:metabolism; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
D001457:Anion Exchange Protein 1, Erythrocyte; D014443:Tyrosine; D017027:Protein Tyrosine Phosphatases