First of all sorry if I'm not in the correct newsgroup...
I was looking at how to measure glycogen synthase in a muscle extract
activity for the first time and a few things are not so clear...
They say that to eliminate the influence of endogenous competitive
effectors and activators, the enzyme extract is diluted 100-fold. To be
sure, you can check the activity with no exogenous G-6-P ( should be real
low ). Then you can measure with 0.1mM G-6-P and 10mM G-6-P ( total GS
activity ) and use the data as you wish afterward...
1) What exactly do represent the GS activity with 0.1mM G-6-P added ? Is
it the physiological state the GS was in before the muscle extraction ?
If so, what happened during the homogenization that causes the 0mM G-6-P
measurement to be different from the 0.1mM one ? Did the I-form change
toward nearly only D-form during the homogenization ? What's happening to
the phosphatases and the kinases during the homogenization and afterward
??
Thanks a million time for your precious help...
ps: please reply to my address so I can see your answer for sure...
--
Edouard Lauzier, B.Sc. elauzier at fse.ulaval.ca
Physical Activity Science Laboratory (418) 656-2131 #2929
(Laval University) G1K 7P4
CANADA
