cytochrome b5

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cy·to·chrome b5

A cytochrome in the endoplasmic reticulum that acts with a number of oxygenases; a deficiency of this cytochrome results in a form of hereditary methemoglobinemia.
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trituberculatus share the same heme-binding motif region, three histidine-rich regions (HXXXH, HXX(X)HH, and Q/HXXHH), and the cytochrome b5 domain (Fig.
Total microsomal CYP and cytochrome b5 were measured according to the method of Omura and Sato, 1964 [16], using the molar extinction coefficients 91 and 185 m[M.
When SARA was induced, acyl-CoA synthetase (ACS) and cytochrome b5 involved in lipid metabolism were up-regulated, phosphoenolpyruvate carboxykinase (PEPCK) involved in glucose metabolism was downregulated, while enolase was up-regulated.
Congenital or inherited causes of methemoglobinemia result due to decreased activity of the enzyme cytochrome b5 reductase resulting in diminished enzymatic reduction of the hemoglobin molecule.
3]) by losing electron is prevented by cytochrome b5 system of the body and normally only 1-2% of hemoglobin is present in ferric state in the body.
Cytochrome b5 reductase deficiency and mental retardation.
Hereditary methemoglobinemia, characterized by a deficiency of NADH-dependent cytochrome b5 reductase, has a wide geographic distribution (2).
The description of the inheritance of congenital cytochrome b5 reductase deficiency as an autosomal recessive condition in the context of the father and two sons being clinically affected is unusual but possible.
The reaction mixture with CYP3A4/OR or CYP3A5/OR was additionally supplemented with purified cytochrome b5 (P450:b5 ratio, 1:1) according to a previously described method (26) before the start of the reaction with NADPH.
Cytochrome b5 reductase activity could not be measured in the neonates because of the lack of technical facilities.
Comparisons of the cytochrome b5-like domain with cytochrome b5 are shown in Figure 3.