1887

Abstract

Summary: Ureases of the cyanobacteria PCC 73110 and PCC 7120 were purified more than 1500-fold to homogeneity by heat treatment and liquid chromatography, reaching specific activities of up to 350 U (mg protein). Both enzymes had a molecular mass of 220 kDa, as shown by native PAGE, and consisted of three subunits (α, β, γ) with molecular masses of 66 kDa (α), 18 kDa ( or 14 kDa (AnabaenalNostoc; β) and 11 kDa (γ). The enzyme of exhibited maximum activity at pH 8.2 and 60 °C, and that of nabaenalNostoc at pH 8.5 and 65 °C; the was 0.25 mM urea for both organisms. Almost identical specific activities were observed in cells grown with urea, ammonia, nitrate or dinitrogen as the source of nitrogen. The ureases from both organisms were heat-stable; no loss of activity was observed during incubation at 70 °C for 15 min.

Loading

Article metrics loading...

/content/journal/micro/10.1099/13500872-141-3-737
1995-03-01
2019-11-13
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/13500872-141-3-737
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