Engineering metabolic biosynthetic pathways has enabled the microbial production of many useful chemicals. However, pathway productivities and yields are often limited by metabolic imbalances. Synthetic regulatory circuits have been shown to be able to balance engineered pathways, improving titers and productivities. Here we developed a negative feedback regulatory circuit based on a malonyl-Co...

Acetyl-CoA hydrolase (Ach1p), catalyzing the hydrolysis of acetyl-CoA, is presumably involved in regulating intracellular acetyl-CoA or CoASH pools; however, its intracellular functions and distribution remain to be established. Using site-directed mutagenesis analysis, we demonstrated that the enzymatic activity of Ach1p is dependent upon its putative acetyl-CoA binding sites. The ach1 mutant ...

It has been shown (1, 2) that in human milk there are N-acetyl-n-glucosamine-containing oligosaccharides which promote the growth of Lactobacillus bifidus var. Penn. In the search for substances with lower molecular weight which would still show a growth-promoting effect in the microbiological test, activity was found in mildly hydrolyzed chitin of crab and lobster shells,’ in P-methyl N-acetyl...

A covalent, catalytic intermediate of cytosolic liver acetyl coenzyme A: arylamine N-acetyltransferase (EC 2.3.1.5) from rapid acetylator rabbits (III/J) was isolated and chemically characterized. The active site was further studied using two covalent inhibitors, [2-3H]iodoacetic acid and bromoacetanilide. Inhibition experiments with [2-3H]iodoacetic acid at pH 6.9 showed that the incorporation...

The urinary excretion of N-acetyl-beta-D-glucosaminidase isoenzymes A and B following kidney transplantation was studied in rats. High enzymuria with permanent marked isoenzyme B excretion occurred from the immediate post-operative period to the irreversible rejection episode. Isoenzyme B could represent as much as 10-40% of total N-acetyl-beta-D-glucosaminidase activity and it reflected the in...

In order to prove this suggestion, a study of the chemistry of acetyl phosphate was undertaken and eventually a method of determination and a simple synthesis were worked out (3). With these available, on oxidation of pyruvate the appearance of a labile organic phosphate was observed (4) which closely resembled acetyl phosphate. The present, communication reports upon t.he isolation of this int...

The capsule polysaccharide of Neisseria meningitidis serogroup B is composed of a homopolymer of alpha-2-->8 linked N-acetyl-neuraminic acid (sialic acid). The enzymes required for sialic acid biosynthesis and polymerization are encoded in region A of the capsule gene complex. We here describe the enzymatic activity of the siaA gene product as determined by biochemical analysis. siaA was overex...

OBJECTIVE Facial nerve dysfunction can vary in severity and recovery is dependent on the character of the injury. N-acetyl-cysteine prevents oxidative stress and cellular damage, and its use in the setting of nerve dysfunction from crush injury has not yet been established. In this study, rats with facial nerve crush injury will be treated with n-acetyl-cysteine or control and functional recove...

Feeding a low fat, biotin-deficient diet to young rats for 1 to 2 weeks leads to a decrease in acetyl coenzyme A carboxylase levels in epididymal adipose tissue with accumulation of the apoenzyme. These changes occur prior to changes in hepatic propionyl coenzyme A carboxylase levels. Acetyl coenzyme A carboxylase levels in liver decrease minimally with biotin deficiency, and little apoenzyme a...