Register      Login
Australian Journal of Biological Sciences Australian Journal of Biological Sciences Society
Biological Sciences
RESEARCH ARTICLE

Pyridine Nucleosidase in Bull Semen ll. Biochemical Properties

KH Giles and KL Macmillan

Australian Journal of Biological Sciences 28(3) 273 - 278
Published: 1975

Abstract

It is most likely a single enzyme (NAD+ nucleosidase) present in semen from most bulls which hydrolyses the ribosyl pyridinium bond in both NAD and NADP. This conclusion is based on the following results: (i) each of 12 semen samples containing nucleosidase activity hydrolysed NAD at the same rate as NADP (r = 0·99); (ii) other untreated semen samples from different bulls which did not hydrolyse NAD were also inactive against NADP; (iii) enzyme denaturation produced by preliminary heating of semen filtrates for 15 min at varied temperatures or by heating at 55°C for varied time intervals caused similar reductions in the rates of NAD and NADP hydrolysis; and (iv) nicotinamide inhibited enzyme activity to the same degree using either NAD or NADP as the substrate.

https://doi.org/10.1071/BI9750273

© CSIRO 1975

PDF (1.5 MB) Export Citation

Share

Share on Facebook Share on Twitter Share on LinkedIn Share via Email

View Dimensions