The study evaluated the effect of extenders and sperm concentration on migration efficiency Malabari buck spermatozoa in bovine cervical mucus. Fresh semen ejaculates collected six different days from three adult healthy bucks were pooled divided into four groups based extender used (tris-egg yolk-based or liposome-based extender) rate extension (200 400 million motile per 0.5 mL) (n=6 group) s...

Using purified enzymes of human origin and patients' sera, we examined factors influencing the in vitro association of pyridoxal phosphate with aspartate aminotransferase (EC 2.6.1.1). The rate of association was markedly retarded by phosphate buffer in comparison with tris(hydroxymethyl)aminomethane or six other buffers. Pyridoxal phosphate at an incubation concentration of 130 mumol/liter rea...

The regulation of the fate of acetyl units derived from the P-oxidation of L( -)-palmitylcarnitine was studied using isolated rat liver mitochondria. Citrate synthesis from acetyl-CoA was dependent upon the concentration of Lmalate, the immediate precursor of oxalacetate in this system. The independence of the rate of citrate formation on the means used to stimulate respiration, e.g. ADP for co...

Although Lactococcus is one of the most extensively studied lactic acid bacteria and is the paradigm for biochemical studies of citrate metabolism, little information is available on the regulation of the citrate lyase complex. In order to fill this gap, we characterized the genes encoding the subunits of the citrate lyase of Lactococcus lactis CRL264, which are located on an 11.4-kb chromosoma...

Palmitoyl CoA inhibited citrate transport from isolated rat liver mitochondria. Under conditions described, 50% inhibition was observed at about 6-8 nmol/mg of mitochondrial protein per ml. The percentage inhibition was inversely proportional to the concentration of the counter-transporting anion in the medium. Although comparable levels of palmitoyl CoA had little effect on malate exit on the ...

Mitochondrial malate dehydrogenase shows a complex regulation pattern in the presence of citrate. Previously published results indicate that this enzyme is activated by citrate in the NAD(+)----NADH direction and inhibited in the opposite direction. Moreover, high concentrations of L-malate or oxaloacetate produce deviations from the Michaelis-Menten behaviour. Results reported in this paper cl...