Effect of sulfhydryl group modification on the activity of bovine ferrochelatase.

Ferrochelatase from Rhodopseudomonas sphaeroides: substrate specificity and role of sulfhydryl and arginyl residues.

Purified ferrochelatase (protoheme ferrolyase; EC 4.99.1.1) from the bacterium Rhodopseudomonas sphaeroides was examined to determine the roles of cationic and sulfhydryl residues in substrate binding. Reaction of the enzyme sulfhydryl residues with N-ethylmaleimide or monobromobimane resulted in a rapid loss of enzyme activity. Ferrous iron, but not porphyrin substrate, had a protective effect...

P-20: Determination of Effect of Melatonin on In vitro Maturation of Bovine Oocytes under Heat Stress

Background: Melatonin (N-acetyl-5-methoxytryptamine) is a multifunctional molecule that mediates several circadian and seasonal processes in animal reproduction. Melatonin and its metabolites are antioxidants and free radical scavengers. Furthermore, melatonin has been shown to act as an indirect antioxidant, and it is able to increase the activity of glutathione synthesis, and many others dire...

The functional size of ferrochelatase determined in situ by radiation inactivation.

Ferrochelatase (EC 4.99.1.1) catalyzes the final step of heme biosynthesis, the insertion of iron(II) into protoporphyrin. It is an integral protein of the inner mitochondrial membrane. The functional size of bovine hepatic ferrochelatase has been studied in situ using radiation inactivation analysis. The functional unit required for enzymic activity in intact mitochondria was found to have a m...

P-110: Effect of Increasing Amount of Oocyte Secreted Factors on Cumulus Expansion of Bovine Cumulus-Oocyte Complexes

Background: In vitro maturation is a good method to decrease cancer risk of superovulation by gonadotropin hormones. A paracrine effect of oocyte secretions on oocyte developmental competence is under investigation. Apart from oocyte maturation, ovulation in vivo requires a precise control of extracellular matrix modification. Cumulus cells secrete hyaluronan to form a muco-elastic extracellula...

Studies on the modification of Dorset - Henly medium for the producrtion of bovine tuberculin