Helen,
I'd like to have a copy -- thanks.
By the way, some years ago we found that the Sigma yeast enolase had a
relatively low specific activity, comparing to the "best" which had been
made in labs. Our tentative investigations indicated that a fraction of
the prep (maybe 50%, if I remember correctly) had undergone an oxidative
modification which altered a single histidine. Since then several groups
have found that such modifications generally convert a histidine to
2-oxohistidine, causing a mass increase of 16. Have you seen any evidence
of heterogeneity consistent with that kind of change? (Normally I'd write
it off to Met going to MetSO, but in this case I'd guess it would be His to
OHis.)
Rod Levine
NIH
Bldg 3, Room 106 MSC 0320
Bethesda, MD 20892-0320
email: rlevine@nih.gov
voice: 1 (301) 496-2310
fax: 1 (301) 496-0599