PEPCK inhibitor?

[Vincent Encomio]

I'm studying anaerobic metabolism in a marine worm that we collect from 
mudflats here in CA.  I am interested in finding an inhibitor for the 
enzyme phosphoenolpyruvate carboxykinase.  Some literature I've looked at 
used 3-mercaptopicolinic acid.  I've looked through Aldrich, Sigma, and 
other catalogs and couldn't find it.  When I asked about custom 
synthesis, the minimum price was $5000, so I said no thanks.  Does anyone 
know if there is a compound that is analogous in its effects on PEPCK 
activity and if it is commercially available.  The only thing I found 
similar (in chemical structure) was 2-mercaptonicotinic acid, but I don't 
know if this would work.  I almost thought it was the same.  The 
difference is that the sulfhydryl group and the COOH group are 
interchanged. If anyone knows if there is a compound I could use that is 
available, please let me know.

Vincent 

vencomio at sfsu.edu