Carbon monoxide, biochemical effects

An enzyme is a protein that speeds up a biochemical reaction without itself experiencing any overall change. In chemical language, such a compound is called a catalyst and is said to catalyze a reaction. Chemists employ a variety of compounds as laboratory catalysts, and many industrial chemical processes would be impracticably slow without catalysis. An automobile s catalytic converter makes use of a metal catalyst to accelerate conversion of toxic carbon monoxide in the exhaust to carbon dioxide. Similarly, our bodies biochemical machinery effects thousands of different reactions that would not proceed without enzymatic catalysis. Some enzymes are exquisitely specific, catalyzing only one particular reaction of a single compound. Many others have much less exacting requirements and consequently exhibit broader effects. Specific or nonspecific, enzymes can make reactions go many millions of times faster than they would without catalysis. 

One hemoglobin adduct, carboxyhemoglobin, is a special case in that it is both an indicator of exposure and an effect. Carboxyhemoglobin is the key biochemical derangement caused by carbon monoxide, so its concentration is directly related to health risk. For other biomarkers that utilize hemoglobin adducts, hemoglobin is not the biochemical target. 

Bing, R.J., J.S.Sarma, R.Weishaar, A.Rackl, and G.Pawlik. 1980. Biochemical and histological effects of intermittent carbon monoxide exposure in cynomolgus monkeys (Macaca fascicularis) in relation to atherosclerosis. J. Clin. Pharmacol. 20(8- 9) 487-499. 

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Several other natural products systems have been studied, some quite extensively, by NMR methodology, however space constraints prohibt detailed discussion of these systems therefore only important leading references will be given. Extensive NMR studies on amino acids and small peptides have been performed by Lauterwein and coworkers [116-119], by Fiat and coworkers [120-123] and others [124]. Several studies have used l O-enriched dioxygen and carbon monoxide to study by NMR techniques the interactions of these biochemically important small molecules with various proteins [125-128]. A number of investigators have explored the properties and interactions of nucleic acid bases [129,130], nucleosides [131,132], nucleotides [133-138] and one report has appeared in which NMR spectroscopy approaches were applied to the study of small molecule-DNA interactions [139]. A recent report describes the careful analysis of the effect of structure on NMR chemical shifts of over forty hydroxyterpenoids [140]. A study of the 1 0 NMR spectroscopy of over thirty steroid ketones, acids, esters and alcohols enriched with has recently appeared [141]. 

Hill, A. V. The combinations of haemoglobin with oxygen and carbon monoxide, and the effects of acid and carbon dioxide. Biochem. J., 1921, 15(5), 577-586. 

A biochemical response to carbon monoxide exposure is deprivation of tissues of O2 needed to carry out metabolic processes. In this case, brain cells are deprived of oxygen, the subject may lose consciousness, and permanent brain damage or death may result. An observable effect of carbon monoxide poisoning may range from lethargy through unconsciousness and even death. 

Hurst KM, Lewis RS. 2010. Carbon monoxide partial pressure effects on the metabolic process of syngas fermentation. Biochemical Engineering 48 159-165. 

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