Mechanism-based inactivation of rabbit muscle phosphoglucomutase by nojirimycin 6-phosphate. Academic Article

abstract

• Nojirimycin 6-phosphate (N6P) was tested as a substrate and inhibitor for phosphoglucomutase (PGM). In the absence of glucose 1,6-bisphosphate (GBP), the incubation of PGM and N6P resulted in the complete inactivation of all enzyme activity. When equimolar amounts of N6P and GBP were incubated together with PGM, the GBP was quantitatively converted to glucose 6-phosphate (G6P) and phosphate. At higher ratios of GBP and N6P (greater than 100) the final concentration of G6P produced was found to be 19 times the initial N6P concentration. These results have been interpreted to suggest that the phosphorylated form of PGM catalyzes the phosphorylation of N6P at C-1. This intermediate rapidly eliminates phosphate to form an imine and the dephosphorylated enzyme. The dephosphorylated enzyme is rapidly rephosphorylated by GBP and forms G6P. The imine is nonenzymatically hydrated back to N6P. Occasionally (5%) the imine isomerizes to a compound that is not processed by PGM.

authors

• Raushel, Frank

published proceedings

• Biochemistry

author list (cited authors)

• Kim, S. C., & Raushel, F. M.

citation count

• 4

complete list of authors

• Kim, SC||Raushel, FM

publication date

• September 1988

publisher

• American Chemical Society (ACS)  Publisher

published in

• Biochemistry  Journal

keywords

• 1-deoxynojirimycin
• Animals
• Catalysis
• Enzyme Activation
• Glucosamine
• Glucose-6-Phosphate
• Glucosephosphates
• Hydrogen-Ion Concentration
• Kinetics
• Magnetic Resonance Spectroscopy
• Muscles
• Phosphates
• Phosphoglucomutase
• Phosphorylation
• Rabbits

PubMed Central ID

• 2974722

Digital Object Identifier (DOI)

• 10.1021/bi00419a022

start page

• 7328

end page

• 7332

volume

• 27

issue

• 19

URL

• http://dx.doi.org/10.1021/bi00419a022