Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by FUKUI, T.
Right arrow Articles by NIKUNI, Z.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by FUKUI, T.
Right arrow Articles by NIKUNI, Z.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1970, Vol. 67, No. 2 211-218
© 1970 Japanese Biochemical Society

research-article

Reaction of Glyoxal with {alpha}-Glucan Phosphorylases from Potato and Rabbit Muscle

TOSHIO FUKUI, ATSUMI KAMOGAWA and ZIRO NIKUNI

Institute of Scientific and Industrial Research, Osaka University Suita, Osaka

The reaction of glyoxal with {alpha}-glucan phosphorylases [EC 2.4.1.1 [EC] ] from potato and rabbit muscle was studied. Both phosphorylases were completely inactivated within an hour by incubating with approximately 1mM of glyoxal at pH7.9 and at 30°C. The rate of reaction depended upon pH. Fall of one pH unit resulted in a decrease of the rate of inactivation to about one-tenth. The rate of inactivation by glyoxal was retarded by the presence of substrates; P1, glucose 1-phosphate and starch. The muscle enzyme was also protected by the presence of its activator, AMP, against the inactivation by glyoxal. More protective effect was observed when both AMP and glucose 1-phosphate was present in the same reaction mixture than in the case of AMP alone. The potato enzyme was not protected by AMP. Less inactivation was attained with either formaldehyde and diacetyl. Glyoxylic acid was not effective. The complete inactivation occurred when approximately 12 moles of 14C-glyoxal were incorporated into the enzyme protein, while the incorporation continued almost linearly up to at least three hours in both enzymes.

Glyoxal-modified potato phosphorylase exhibited little increase in the absorbance around 330 mµ, and sedimented as a single and symmetrical boundary with the same sedimentation velocity as the native enzyme upon ultracentrifugation. Total amino acid analysis of the fully inactivated enzyme revealed loss of lysine and arginine residues. Determination of arginine content showed that arginine residues were modified when the potato enzyme was completely inactivated.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.