SUBSTRATE SPECIFICITY OF BRAIN HEXOKINASE

The hexose specificity of hexokinase in brain from various species.

the ketokinases from different sources differ so widely (liver <0-5 mm and rabbit muscle 0-2M; Hers, 1955). The constant calculated for the locustmuscle enzyme, 5-5 mm, is of the same order as that found for hexokinase from yeast, 1-7 mm, by Slein et al. (1950). We consider that locust muscle contains a single, non-specific hexokinase and that the enzyme is similar to that found in yeast and in...

Substrate specificity of rat brain ceramidase.

In this study, the substrate specificity of a newly identified rat brain ceramidase (CDase) was investigated. To this end, the major functional groups and stereochemistry of ceramide (Cer) were evaluated for their influence on the hydrolysis of substrate by this CDase. The results showed that, of the four possible stereoisomers of Cer, only the natural d-e-C(18)-Cer isomer was used as substrate...

Hexokinase specificity of some tumor tissue extracts.

The substrate specificity of hexokinase preparations from Ehrlich ascites cells, a spontaneous adenocarcinoma, Jensen sarcoma, and Walker carcinoma was studied with a number of sugars which differed in structure from glucose at one or more carbon atoms used as substrates. A marked variat ion in specificity was found. The preparations from Jensen sarcoma and Ehrlich ascites cells were relatively...

The substrate specificity of brain microsomal phospholipase D.

Neurotransmitters activate a phospholipase D that is though to specifically hydrolyse phosphatidylcholine. This enzyme has a unique property known as transphosphatidylation: in the presence of an appropriate nucleophilic receptor such as an alcohol, phospholipase D will catalyse the production of phosphatidyl-alcohol. We have studied phospholipase D using an in vitro assay that uses [3H]butanol...

Substrate Specificity of MMPs