1887

Abstract

The cyanophycin granule polypeptide (CGP) is known to serve as a nitrogen reserve protein in cyanobacteria and is mobilized during nitrogen starvation. An exopeptidase, provisionally called cyanophycinase, which degraded CGP in vitro has been studied, and its product characterized, in two N-fixing species. The enzyme had a pH optimum of 85, had no requirement for monovalent or divalent cations and was inhibited by -arginine and -aspartic acid. The product of this enzyme was an aspartic acid-arginine dipeptide. A higher activity of both arg-poly(asp) synthetase and cyanophycinase was observed in extracts of heterocysts of both species than in vegetative cells. This supports the view that CGP has a dynamic role in nitrogen metabolism of cyanobacteria as well as a storage function.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-125-1-17
1981-07-01
2019-12-15
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-125-1-17
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