1887

Abstract

Summary: Mannitol dehydrogenase (EC 1.1.1.138) has been purified to homogeneity from fruit bodies of values of 115000 were determined by gel filtration and 130000 by rate zonal ultracentrifugation. The sedimentation coefficient is 6.5S. The native protein is composed of four subunits of 29000. The enzyme is specific for NADP, and shows low activity with sorbitol. Normal Michaelis-Menten kinetics are exhibited for both mannitol and NADP, giving K values of 16.2 mM and 36μM respectively at pH 7.0. The K value for NADPH is 38.5μM and that for fructose approximately 1.2 M. The is 591 μM min (mg protein) for mannitol synthesis and 5μmol min (mg protein) for fructose synthesis at pH 7.0. Inhibition of fructose synthesis by NADPH is stronger than inhibition of mannitol synthesis by NADP. The results are discussed with respect to the control of enzyme activity under physiological conditions.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-131-11-2885
1985-11-01
2019-11-20
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-131-11-2885
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error