
TY  - JOUR
A1  - Giles, KH 
A1  - Macmillan, KL 
T1  - Pyridine Nucleosidase in Bull Semen ll. Biochemical Properties
JF  - Australian Journal of Biological Sciences
JO  - Aust. Jnl. Of Bio. Sci.
Y1  - 1975
VL  - 28
IS  - 3
SP  - 273
EP  - 278
KW  - 
UR  - https://doi.org/10.1071/BI9750273 
N2  - 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. 
ER  -

