No abstract

Silent information regulators are NAD(+)-dependent enzymes that display differential specificity toward acetylated substrates. This report provides first evidence for deacetylation activity of CobB1 in Streptomyces coelicolor. The protein is highly conserved in streptomycetes. The CobB1 protein catalytically removes the acetyl group from acetylated bovine serum albumin. In the absence of NAD+ or when NAD+ was substituted with nicotinamide, deacetylation was stopped. We isolated gene encoding AcetylCoA synthetaseA. The recombinant enzyme produces Acetyl-CoA from acetate. The highest acsA-mRNA level was detected in cells from the exponential phase of growth, and then decreased in transition and stationary phases of growth. Acetylated acsA loses the ability to transfer acetate to CoA. Deacetylation of the enzyme required CobB1, ATP-Mg2, and NAD+. Using specific antibodies against acetylated lys, CobB1, and acsA, we found relationship between level of CobB1 and acetylation of acsA, indicating that CobB1 is involved in regulating the acetylation level of acsA and consequently its activity. It was found that 1-acetyl-tetrahydroxy and 1-acetyl pentahydroxy antraquinone inhibit the deacetylation activity of CobB1.

Fallow deer (Dama dama) are important meat producing species providing venison and other products to an international market. The present study investigated the effects of different feed rations on the growth, carcass characteristics and physical attributes of the longissimus lumborum (LL) and semitendinosus (SET) muscles of 45 farm-raised male fallow deer. The animals were divided into three separate groups: 15 pasture-fed (P), 15 pasture-fed and supplemented with barley (B), and 15 pasture-fed and supplemented with barley and lysine (BL). The animals were slaughtered at an average age of 17 months at three time points: after 155, 169 and 183 days on feed. The addition of barley to the feed ration significantly increased weight gain and had positive effects on slaughter and carcass weights, dressing-out proportion, carcass composition, the weight of LL muscle, and increased the redness, yellowness and chroma values of LL muscle. The supplementation with lysine reduced the amounts of carcass and internal fats without compromising other economically important traits.