Behyar Zoghi b0z9706 at
Mon Oct 16 10:07:35 EST 1995

Hi Dr. Matsuda,

	As you mentioned vanadate has been used as tyrosine phosphatase 
inhibitor. It seems that pervanadate has better effect on enzyme 
inhibition than vanadate by itself. Solution of pervanadate can be 
prepared by mixing vanadate with h2o2 for 15 minutes at 22 degreeC. This 
can be followed by the addition of catalase 200ug/ml to remove 
residual h2o2. This procedure results in the generation of the 
peroxidized form of vanadate which is stable for 2 hrs without further 
addition of h2o2. Different concentration of vanadate and h2o2 can be 
used. 100uM vanadate +3mM h2o2 have been used in couple of experiments. for 
further information following papers can be useful:

1) "The insulinomimetic agents H2O2 and Vanadate stimulate protein 
tyrosine phosphorylation in intact cells"
	Dahna Heffetz,Hana Bushkin (1990) JBC 265,#5,Feb 15.pp.2896-2902

2) "A combination of H2O2 and vanadate concomitantly stinmulate protein 
tyrosine Phosphorylation and polyphosphoinositide breakdown in different 
cell lines"
	Yehiel Zick and Roni Sagi-Eisenberg.(1990) Biochemistry.29,10240-10245

3) "Peroxides of vanadate induces activation of phospholipase D in HL-60 
	Sylvain Bourgoint,JBC.(1992),267,17,June 15,pp.11908-11916

4) "Vanadate activates or inhibits receptor and non-receptor protein 
tyrsonie kinases in cell-free experiments,depending on its oxidation state"
	Gerard Elberg,Jinping Li.JBC (1994),269,13,April 1,pp.9521-9527.

5) Fantus,I.G 1989,Biochemistry 28,8864-8871

If you have further question I would be happy to answer (if I know!)
				Good Luck

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