The presence of a high-Km hexokinase activity was tested in both dog and boar spermatozoa. Hexokinase kinetics from dog extracts showed the presence of a specific activity (dog-sperm glucokinase-like protein, DSGLP), in the range of glucose concentrations of 4-10 mM, whereas boar sperm did not show any DSGLP activity. Furthermore, dog-sperm cells, but not those of boar, showed the presence of a protein which specifically reacted against a rat-liver anti-glucokinase antibody. This protein also had a molecular weight equal to that observed in rat-liver extracts, suggesting a close similarity between both the proteins. This glucokinase-like protein was distributed in the peri- and post-acrosomal zones of the head, and the midpiece and principal piece of tail of dog spermatozoa. These results indicate that dog spermatozoa have functional high-Km hexokinase activity, which could contribute to a very fine regulation of their hexose metabolism. This strict regulation could ultimately be very important in optimizing dog-sperm function along its life-time. © 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
|Publication status||Published - 16 Jul 2004|
- DSGLP, dog-sperm glucokinase-like protein
- Glucokinase-regulatory protein
- High-K hexokinase m
- PBS, phosphate-buffered saline
- SDS, sodium dodecyl sulfate
- TRITC, tetramethylrhodamine isothiocyanate