The sodium-dicarboxylate cotransporter of the renal proximal tubule, NaDC-1, reabsorbs filtered Krebs cycle intermediates and plays an important role in the regulation of urinary citrate concentrations. (1) Low urinary citrate is a risk factor for the development of kidney stones. As an initial step in the characterization of NaDC-1 regulation, the genomic structure and functional properties of...

The lack of ubiquinone in the isolated succinate-ubiquinone reductase (Complex II) and in some preparations of ubiquinone-binding protein (QPs) has caused some concern about the nature of interaction between ubiquinone and QPs. When a low concentration of radioactively labeled ubiquinone derivative in dilute detergent solution was incubated with delipidated or intact succinate-ubiquinone reduct...

CLINICAL CHEMISTRY, Vol. 40, No. 12, 1994 2321 ues <35 kAU/L, n = 26), we used the modified t-test (5) because the theoretical F-value differs significantly from the calculated one. We obtained t = -0.027 and t = 2.0 19 (for chosen level of significance = 95%); thus, the slopes of the two regression lines do not differ significantly. We conclude that the reference interval determined by the ear...

The aim of this research was to develop a suitable method of succinate dehydrogenase activity assay in situ for different industrial yeast strains. For this purpose different compounds: EDTA, Triton X-100, sodium deoxycholate, digitonin, nystatin and beta-mercaptoethanol were used. The permeabilization process was controlled microscopically by primuline staining. Enzyme assay was conducted in w...

Elucidation of the molecular mechanisms of activation of G protein-coupled receptors (GPCRs) is among the most challenging tasks for modern membrane biology. For studies by high resolution analytical methods, these integral membrane receptors have to be expressed in large quantities, solubilized from cell membranes and purified in detergent micelles, which may result in a severe destabilization...

The transfer of citrate, succinate, a-ketoglutarate and pyruvate was studied with everted sacs of hamster small intestine and evidence presented for specific transfer mechanisms for each of these. All four intermediates studied were rapidly removed from the mucosal fluid and appeared in the serosal fluid in the presence of metabolites. Only in the case of citrate, where consistently high recove...

In the course of investigations on the respiration and the cytochrome-succinic oxidase system ofram spermatozoa (Mann, 1945, 1951a, b; Humphrey & Mann, 1949) two phenomena have been observed: (i) it was found that as the result of freezing and subsequent thawing, or after prolonged storage of semen in vitro, there was a leakage of cytochrome c from the spermatozoa into the surrounding fluid; (i...

Case presentation: A previously healthy 3-year-old boy presented with difficulty understanding commands and developed impairment of spoken language that lasted four months remitted spontaneously. After 10 months, he suffered again regression. Electroencephalogram (EEG) revealed electrical status epilepticus during sleep (ESES). He was treated sulthiame, sodium valproate clobazam partial improve...

Two serine transhydroxymethylase activities have been purified from a facultative methylotrophic bacterium. One enzyme predominates when the organism is grown on methane or methanol as the sole carbon and energy source, whereas the second enzyme is the major isoenzyme found when succinate is used as the sole carbon and energy source. The enzyme from methanol-grown cells is activated by glyoxyla...