Down-regulation ("curb") of hexose transport in Chinese hamster lung fibroblasts has been studied in a metabolic mutant highly defective in phosphoglucose isomerase (PGI; glucosephosphate isomerase; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9). In the parental strain (PGI+) glucose as well as glucosamine and mannose were able to elicit a curb of the hexose transport system. In the PGI mut...

Segregation of paternal marker alleles in the progeny of a single boar was used to estimate linkage between the marker genes and associations of these genes with quantitative trait loci (QTL). The sire was heterozygous at four polymorphic marker loci, haptoglobin (HP), glucosephosphate isomerase (GPI), phosphogluconate dehydrogenase (PGD), and esterase D (ESD), and sired 30 litters during an 8-...

Approximately 260 Streptomyces strains were isolated from neutral pH farmland soil and evaluated for their ability to produce glucose isomerase. The number of acidophilic Streptomyces organisms growing at pH 4.0 was low, i.e., 10 organisms per g of soil. All of the isolates showed glucose isomerase activity when they were grown in a medium containing d-xylose, an inducer for glucose isomerase. ...

The conversion of hexose monophosphate to sedoheptulose 7phosphate, first detected by Bonsignore et al. (1) in dialyzed liver extracts, and by Dische (2) in red cell hemolysates, can be attributed to the presence of transketolase and transaldolase in these extracts (3, 4). With highly purified preparations of transketolase and transaldolase, free of phosphoglucose isomerase and xylulose 5-phosp...

The capacity to synthetize isopropylmalate isomerase (EC 4.2.1.33) by Neurospora crassa increased during induction in the presence of cycloheximide but was inhibited by proflavine and other inhibitors of RNA synthesis. Turnover of the enzyme once formed appeared negligible, but the message (measured as enzyme-forming capacity) had a half-life of 4 to 8 min. A comparison of the kinetics of induc...