Sarcosine dehydrogenase

NADPH DEHYDROGENASE NITRATE REDUCTASE PROTOPORPHYRINOGEN OXIDASE SARCOSINE DEHYDROGENASE SULFITE REDUCTASE FoFi-ATPase (and RELATED PROTONTRANSPORTING ATPases)... 

SARCOSINE DEHYDROGENASE SARCOSINE OXIDASE SATURATION Saturation function,... 

Dimethylglycine and sarcosine dehydrogenases in the catabolism of choline (Section 14.2.1). In these reactions, a methyl group in the substrate is oxidized by FAD, then the intermediate adduct undergoes hydrolysis to release formaldehyde, which reacts with tetrahydrofolate to form 5,10-methylene tetrahydrofolate. 

Porter DH, Cook RJ, Wagner C. 1985. Enzymatic properties of dimethylglycine dehydrogenase and sarcosine dehydrogenase from rat liver. Arch Biochern Biophys 243 396-407. 

Figure 8. ESR (upper) and ENDOR (lower) spectra from flavoproteins at — 160°C. a, Semiquinone radicals from the one-electron reduction of electron-transfer flavoprotein (ETF) b, semiquinone radicals from the one-electron reduction of sarcosine dehydrogenase. From [144], with permission.

Porcine ETF and MCAD have been shown to form a specific association, with 1 1 stoichiometry, and cross-linking studies showed preferential binding of porcine MCAD to the P subunit of ETF. More recently, mammalian ETF has been detected complexed to MCAD and sarcosine dehydrogenase in the crude extract of porcine liver [Parker, A and Engel, P.C.-submitted] and these complexes have also been partially purified. 

Sarcosine dehydrogenase (EC 1.5.99.1). Hypersar-cosinemia and hypersarcosinuria. Some cases with mental retardation. Probably benign. 

Sarcosine dehydrogenase (EC l.S.99.1) a mitochondrial flavoprotein (the flavin is covalently bound) catalysing conversion of sarcosine to glycine and a one-carbon unit at the oxidation level of formaldehyde (or bound -CHj-). The metabolic fate of the one-carbon unit depends on the availability of tet-rahydrofolate (THF). In the absence of THF, the products are glycine and formaldehyde. See One-carbon cycle. 

The effects ensuing from the interaction between membrane-bound sarcosine dehydrogenase and the surrounding lipids as well as the effects of membrane fluidity were studied. A 25-fold activation was observed upon... 

Sanfilippo syndrome, type C Sanfilippo syndrome, type D Santavuori disease Saposin B deficiency Sarcosine dehydrogenase deficiency Scheie syndrome Schindler disease Segawa disease... 

Sarcosine dehydrogenase has been solubilized and separated from the electron transport chain in a number of laboratories recently 89, 93, 94). Hoskins and Mackenzie 94) report that the dehydrogenase is flavin adenine dinucleotide (FAD)-dependent. The deh3rdn enation of sarcosine may be... 

Results forthcoming from the literature do not always assist in building a picture of events. The observation [65] that 2- and 4-hydroxylation of biphenyl was competitively inhibited by polysorbate 80 in the hamster contrasts with the finding that in the rat, polysorbate 80 (2mM) had no effect on the linear microsomal demethylation of aminopyrine (also a Type V substrate) [66]. The question arises whether surfactants such as polysorbate 80 produce their effects by interaction as an alternative substrate or by perturbation of a membrane bound enzyme system. Commercial samples of polysorbate 80, Brij 35 and Triton X-100 all enhance the activity of a sarcosine dehydrogenase isolated from a strain of Pseudomonas, due to the presence of free oleic acid in these non-ionic surfactants. Deoxycholate and a sarcosine surfactant (N-dodecanoyl N-methyl glycine) inhibit activity [67]. Correlations between the CMC of the non-ionic surfactants and the concentrations required for enzyme activation are seen in Table 10.9. 

Table 10.9 Correlation of CMC with activation or inhibition of sarcosine dehydrogenase activity.

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