Biochemistry of NO

NO is a diatomic free radical gas. NO is relatively nonreactive, for example, in comparison with other biologically important radicals, such as hydroxyl or superoxide anion (Stamler et al., 1992). NO radical should be considered one of a family of redox-related congeners, as NO (nitrosonium) and NO (nitroxyl), which can be formed from NO by physiologically relevant redox mechanisms, have distinct preferred targets with which they interact (Stamler et ai, 1992 Stamler, 1994). Table II lists some of the preferred reactions and targets of the redox-related forms of NO. 

The physical properties and chemistry of NO determine its biological fate and potential sites for interaction. NO is a highly diffusible compound because of its low molecular weight and reasonable hydrophobicity and solubility, NO is theoretically able to reach anywhere within cells and tissues (Feldman et al., 1993). Practical limits exist on the diffusion potential of NO, however, due to its many possible chemical interactions. The greatest factor limiting the availability of NO may be its rapid interaction with 

TABLE II Biochemical Interactions of Nitric Oxide (NO) and Related Species 

ONOO- DNA Strand breaks, deaminated bases 

There are multiple sites of NO interaction with biochemical pathways, partly depending on the NO species encountered (Nathan, 1992 Stamler et al., 1992) (Table II). Nearly all cell components are possible targets, including proteins, carbohydrates, lipids, and nucleic acids, in addition to various small molecules. Most interactions of NO with enzymes cause inactivation, be it with heme groups, thiols, or other sites, with the notable exception of guanylate cyclase, which is stimulated by NO (Katsuki et al.. 

---

As we shall see, a thorough appreciation for the chemistry and biochemistry of -NO is essential for any fimdamental understanding of its critical roles in a multitude of biologically... 

Many biochemical reactions depend on the presence of metal ions. These ions may be present in specific coordination complexes or may act to facilitate or inhibit reactions in solution. In the first part of this chapter, we describe a few of these compounds and reactions, together with the biochemistry of NO, which has many functions that have only recently been discovered. 

Only three kinds of octopus have been confirmed to be biolu-minescent Japetella, Eledonella, and Stauroteuthis syrtensis (Johnsen et al., 1999). No information is available concerning the biochemistry of their luminescence. 

Xenobiotic A foreign compound that has no role in the normal biochemistry of a living organism. A normal endogenous compound to one species can be a xenobiotic to another species. 

A convenient preparative method for conjugated nitroalkenes has been developed based on the reaction of nitrogen oxides. Nitric oxide (NO) is commercially available and used in the industry for the mass production of nitric acid. Nitric oxide is currently one of the most studied molecules in the fields of biochemistry, medicine, and environmental science.47 Thus, the reaction of NO with alkenes under aerobic conditions is of a renewed importance.48... 

In vitro activation of soluble guanyl cyclase and nitric oxide release a comparison of NO donors and NO mimetics Biochemistry 40 (2001),... 

NO donors have been used for more than a century in the treatment of cardiovascular diseases. Clearly, the NO/cGMP system plays a major role in platelet inhibition in vivo and in vitro, however, the complex regulation of cGM P levels, as well as the crosstalk to the cAMP system, makes it a signaling network that is not yet fully understood. The contribution of cGMP-independent mechanisms in NO signaling in platelets is far from clear. Careful use of the crucial genetically altered mouse models, the variety of NO donors with clear differences in biochemistry and functional platelet effects as well as the many so-called specific activatory or inhibitory research tools will certainly help to elucidate the still unknown areas of NO signaling in platelets in the near future. 

Endou H, Koseki C, Hasmura S, et al. 1982. Renal cytochrome P-450 Its localization along a single nephron and its induction. In Morel F, ed. Biochemistry of kidney functions. INSERM Symposium No. 21. Elsevier Biomedical Press B.V. 319-327. 

Kurreck, J. Antisense Technologies Improvement through Novel Chemical Modifications. European Journal of Biochemistry 270 no. 8 (2003) 1628-1644. 

Harbome, J.B. (1999B) The comparative biochemistry of ph 4oalexin induction in plants. Biochem. System. Ecol., 27,335-67 (unfortunately this otherwise useful paper is replete of wrong or incomplete structural representations and no reference is given to the original chemical publications). 

Enzymology is a large and complex subdivision of biochemistry, and no attempt will be made to cover it in this book. The reader who requires a review of enzyme kinetics and mechanisms is referred to the many currently available and excellent textbooks of biochemistry. 

Growth and reproduction inhibited at high dose. No malformed nestlings at low dose, but femur lengths were shorter than controls. Altered liver biochemistry of nestlings from parents fed low dose... 

---