Nitrite Reductase Function of Deoxymyoglobin

Nitrite reductase function of deoxymyoglobin: oxygen sensor and regulator of cardiac energetics and function.

Although the primary function of myoglobin (Mb) has been considered to be cellular oxygen storage and supply, recent studies have suggested to classify Mb as a multifunctional allosteric enzyme. In the heart, Mb acts as a potent scavenger of nitric oxide (NO) and contributes to the attenuation of oxidative damage. Here we report that a dynamic cycle exists in which a decrease in tissue oxygen t...

Deoxymyoglobin is a nitrite reductase that generates nitric oxide and regulates mitochondrial respiration.

Previous studies have revealed a novel interaction between deoxyhemoglobin and nitrite to generate nitric oxide (NO) in blood. It has been proposed that nitrite acts as an endocrine reservoir of NO and contributes to hypoxic vasodilation and signaling. Here, we characterize the nitrite reductase activity of deoxymyoglobin, which reduces nitrite approximately 36 times faster than deoxyhemoglobin...

Structural Plasticity and Function in Cytochrome cd1 Nitrite Reductase

Nitrite Reductase in Rice Seedlings

1. In rice seedlings synthesis of methyl viologen-nitrite reductase was stimulated by light, as was that of NADH-nitrate oxidoreductase (EC 1.6.6.1). A small residual effect of light on the synthesis of the enzymes persisted in the dark for a short time. 2. In etiolated seedlings exposed to light and nitrate, a lag period of 3 h was necessary before enzyme synthesis commenced, whereas in green ...

Activation of Nitrite Reductase from Escherichia coli

Nitrite reductase from Escherichia coli K12 requires the presence of NAD+, one of the products of the reduction ofNO2by NADH, for full activity. The effect is observed with both crude extracts and purified enzyme. NAD+ also acts as a product inhibitor at high concentrations, and plots of initial rate against NAD+ concentration are bell-shaped. The maximum occurs at about 1 mM-NAD+, but increase...