ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
A NAD specific proline-dehydrogenase was found in pumpkin (Cucurbita moschata Poir. cv. Dickinson Field) which oxidized proline to Δ1-pyrroline-5-carboxylate. NADP did not substitute for NAD and L-proline-methyl-ester and thiazolidine-4-carboxylate were substrates in the reaction, at a rate of 107% and 33% respectively, of the rate with L-proline. Pumpkin cotyledons contained the bulk of the enzyme activity with 90% of the activity being in the soluble fraction. Proline-dehydrogenase, which was not treated at high temperature, was stable at –10°C for 4 months in the presence of high ammonium sulfate concentration. The Michaelis constant for NAD was 2.2 mM and for L-proline was 2.5 mM. At 5 mM NADP, a 40% non-competitive inhibition of proline-dehydrogenase was obtained, while 50 μM NADP was sufficient to induce 20% inhibition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1974.tb03749.x
