Methanopyrus kandleri is a hyperthermophilic methanogenic archaeon, which grows on H(2) and CO(2) as its sole energy source. Its growth temperature optimum is 98 degrees C. One of the interesting characteristics of this archaeon is its high intracellular salt content. The organism has been reported to contain the trianionic cDPG (cyclic 2,3-diphosphoglycerate) and K+ at concentrations of 1.1 an...

It is now well-established that folic acid, taken peri-conceptionally, can reduce the risk of neural tube defects (NTDs). Recent work has demonstrated that an abnormality of homocysteine metabolism is a critical factor. The gene for 5,10 methylenetetrahydrofolate reductase, an enzyme important in homocysteine metabolism, was studied in relation to NTDs. To determine the frequency of the allele ...

Genomic manipulations using site-specific recombinases rely on their applied characteristics in living systems. To understand their applied properties so that they can be optimally deployed, we compared the recombinases FLP and Cre in two assays. In both Escherichia coli and in vitro, FLP shows a different temperature optimum than Cre. FLP is more thermolabile, having an optimum near 30 degrees...

Mutant forms of DnaA protein, inert in a replication system composed of other purified proteins, are "activated" by DnaK and GrpE heat shock proteins (Hupp, T. R., and Kaguni, J. M. (1993) J. Biol. Chem. 268, 13137-13142). The effect of these heat shock proteins on DnaA5 and DnaA46 protein was separated from the event of DNA synthesis by incubation in two stages. Components necessary during the...

PURPOSE The aim of this case-control study was to investigate the relationship between homocysteine (tHcy), 5,10 methylene tetrahydrofolate reductase (MTHFR) C677T genotype, folate and vitamin B12 status, and retinal vein occlusion (RVO). METHODS Subjects with RVO (n = 106) were recruited from outpatient and inpatient sources. Controls (n = 98) were selected to achieve a similar age and sex d...

Affinity chromatography based on the complex formation of the modified nucleoside Q with boronic acid has been applied to the isolation of specific tRNA precursors containing this modified nucleoside. When [32P]RNA isolated from an Escherichia coli strain containing a thermolabile ribonuclease P was chromatographed on dihydroxyboryl-substituted cellulose, the precursors for asparagine, aspartat...

Hemoglobin is oxidized to methemoglobin by products formed during the oxidation of a number of different substances. With some of these substances, both oxygen consumption and hemoglobin oxidation are accelerated by thermolabile constituents of pneumococci; with others of the easily oxidized substances, neither reaction seems to be influenced by the presence of the bacterial substances. The sam...

The yeast Cdc7 function is required for the G1/S transition and is dependent on passage through START, a point controlled by the Cdc28/cdc2/p34 protein kinase. CDC7 encodes a protein kinase activity, and we now show that this kinase activity varies in the cell cycle but that protein levels appear to remain constant. We present several lines of evidence that periodic activation of CDC7 kinase is...

Crude preparations of bovine testicular hyaluronidase (1) depolymerize both hyaluronic acid (HA) and chondroitinsulfuric acid (CSA). Since a series of enzyme preparations with a wide range (loo-fold) of purity shows a constant ratio of activities toward both substrates when examined by a turbidimetric method of assay, the conclusion was drawn that both activities were most likely assignable to ...