Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biochem. 1997 Jul;122(1):122-8.

Characterization of a human placental fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase.

Author information

  • 1Department of Biochemistry, School of Pharmaceutical Sciences, Nagasaki University.

Abstract

A full-length cDNA, which encodes a human placental fructose-6-phosphate,2-kinase/ fructose-2,6-bisphosphatase, was constructed and expressed in Escherichia coli. The expressed protein, purified to homogeneity, showed a molecular weight of 58,000 by gel electrophoresis under denaturing conditions, compared to the deduced molecular weight of 59,410. The N-terminal sequence of 15 amino acids coincided with that of the deduced sequence. The active enzyme was a dimer as judged by molecular sieve filtration. The expressed enzyme was bifunctional with Vmax values of 142 and 0.2 milliunits/mg for the kinase and phosphatase activities, respectively. The phosphatase activity was extremely low, because one phosphatase active site residue was mutated, and consequently the kinase/phosphatase ratio was the highest among the known isozymes. Furthermore, the enzyme was phosphorylated by cAMP-dependent protein kinase, protein kinase C and also by [2-32P]fructose-2,6-bisphosphate. Phosphorylation by cAMP-dependent protein kinase and protein kinase C increased the maximal Fru-6-P,2-kinase activities by 1.8- and 1.1-fold, respectively. These results suggested that placental fructose-6-phosphate,2-kinase/ fructose-2,6-bisphosphatase is important in maintaining and regulating a relatively high rate of glycolysis in placenta.

PMID:
9276680
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for J-STAGE, Japan Science and Technology Information Aggregator, Electronic
    Loading ...
    Write to the Help Desk