Lactoyl-glutathione

Glyl Glyoj lase B. juncea S-D-Lactoyl- glutathione Tobacco Chlorophyll content of detached leaves 81... 

M. Calvin This is really a point of semantics. It means that your product, whatever it may be—the lactoyl glutathione—does react with ninhydrin. 

E. Racker There is further evidence lactoyl glutathione gives a negative nitro-prusside test and a positive hydroxylamine test. The nitroprusside test becomes positive on alkaline hydrolysis of the ester and the hydroxamic test becomes negative. 

Acetyl glutathione Lactoyl glutathione Ethyl butyrate... 

E. Racker It is quite jslear that DPN is not involved directly in the glyoxylase reaction. I tried to point out in the talk that this is of particular interest. Glyoxylase may represent a primitive mechanism of thiol-ester formation which does not involve nucleotide participation and it would therefore be very valuable to know more about the detailed mechanisms. On the other hand, it is quite true that once lactoyl glutathione is formed, secondary nucleotide-linked reactions may take place. 

E. Racker With purified preparation of glyoxalases we obtained the zinc salt of D-lactic acid which was not oxidized by muscle lactic dehydrogenase. I may add t o this point that synthetic preparation of n, L-lactoyl glutathione which Dr. Wieland has sent us was split to completion by glyoxalase II, which means that both d- and L-lactic acid can be formed and therefore the specificity of the over-all reaction must be due to glyoxalase I. 

T. Wieland The last preparation I have sent to 3 ou was n-lactoyl glutathione. 

T. Wieland We may conclude this from an experiment with lactoyl thiophenol. If the lactoyl group would be transferred to the amino group of glutathione then the ninhydrin reaction must disappear. 

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