Biliverdin reductase-A is a pleiotropic enzyme involved not only in the reduction of biliverdin-IX-alpha into bilirubin-IX-alpha, but also in the regulation of glucose metabolism and cell growth secondary to its serine/threonine/tyrosine kinase activity. Together with heme oxygenase, whose metabolic role is to degrade heme into biliverdin-IX-alpha, it forms a powerful system involved in the cel...

The effect of nitrogen form (NH(4)-N, NH(4)-N + NO(3) (-), NO(3) (-)) on nitrate reductase activity in roots and shoots of maize (Zea mays L. cv INRA 508) seedlings was studied. Nitrate reductase activity in leaves was consistent with the well known fact that NO(3) (-) increases, and NH(4) (+) and amide-N decrease, nitrate reductase activity. Nitrate reductase activity in the roots, however, co...

A procedure for the isolation and partial purification of three hydroxymethylglutaryl coenzyme A reductase phosphatases in their native high molecular weight form from rat liver microsomes is described for the first time. Reductase phosphatase Ex (Mr 90,000), IM (Mr 75,000), and IIM (Mr 180,000) were purified 132-, 55-, and 98-fold, respectively. Treatment with 80% ethanol irreversibly inactiva...

This study was undertaken to search for the endogenous dithiol cofactor of the reductases of the vitamin K cycle. As a starting point, the redox-active lipophilic endogenous compounds lipoic acid and lipoamide were looked at. The study shows that microsomes contain NADH-dependent lipoamide reductase activity. Reduced lipoamide stimulates microsomal vitamin K epoxide reduction with kinetics comp...

Aldo-keto reductase family 1 member C3 has recently been regarded as a potential therapeutic target in castrate-resistant prostate cancer. Herein, we investigated whether berberine delayed the progression of castrate-resistant prostate cancer by reducing androgen synthesis through the inhibition of Aldo-keto reductase family 1 member C3. Cell viability and cellular testosterone content were mea...

Sorbitol production in the renal medulla increases in dehydrated rats, indicating that aldose reductase activity varies with the state of hydration. This response could be due to an increased synthesis of the enzyme (Moriyama T et al. J Biol Chem 1989:264:16810-16814) and/or a change in aldose reductase activity caused by acute changes in intracellular ionic composition, ionic strength, osmolal...

Klebsiella aerogenes W70 could grow aerobically with nitrate or nitrite as the sole nitrogen source. The assimilatory nitrate reductase and nitrite reductase responsible for this ability required the presence of either nitrate or nitrite as an inducer, and both enzymes were repressed by ammonia. The repression by ammonia, which required the NTR (nitrogen regulatory) system (A. Macaluso, E. A. B...

Aldose reductase (alditol:NADP+ oxidoreductase, EC 1.1.1.21), an enzyme that converts glucose to sorbitol, the first step of the polyol pathway, has been implicated in secondary complications of diabetes, such as cataracts, retinopathy, neuropathy, and nephropathy. Aldose reductase inhibitors have been observed to prevent or delay the onset of these complications; however, more potent and speci...

The assimilation of nitrate in plants involves the reduction of nitrate to ammonia in two steps. The first step requires nitrate reductase, a nitrate-inducible enzyme. When seedlings of squash (Cucurbita maxima L.) were treated with nitrate, both nitrate reductase activity and protein were induced in the cotyledons. Poly(A)(+) RNA was prepared from cotyledons of nitrate-treated seedlings and wa...

AIMS To evaluate the mitochondrial respiratory enzyme activities in blood cells of Leber's hereditary optic neuropathy (LHON) with 11778 point mutation of mitochondrial DNA. METHODS Assays for the activities of NADH-cytochrome c reductase (complex I+complex III), succinate-cytochrome c reductase (complex II+complex III), and cytochrome c oxidase (complex IV) on blood cell mitochondria of seve...