Disease relevance of propanal

• Adenosylcobalamin-dependent diol dehydratase of Klebsiella oxytoca is apparently not stereospecific and catalyzes the conversion of both (R)- and (S)-1,2-propanediol to propionaldehyde [1].
• The activities of aldehyde dehydrogenases using benzaldehyde and propionaldehyde as substrates and NADP and NAD as coenzymes were determined in normal liver, hepatocyte nodules and hepatocellular carcinomas from male Wistar rats [2].
• An Escherichia coli strain was constructed for high-level production of His8-PduP, which was purified by nickel-affinity chromatography and shown to have 15.2 micromol min(-1) mg(-1) propionaldehyde dehydrogenase activity [3].
• PduP is a coenzyme-a-acylating propionaldehyde dehydrogenase associated with the polyhedral bodies involved in B12-dependent 1,2-propanediol degradation by Salmonella enterica serovar Typhimurium LT2 [3].
• The fact that both Ado-B12-dependent diol dehydratase and propionaldehyde dehydrogenase are associated with the polyhedral bodies is consistent with the proposal that these structures function to minimize propionaldehyde toxicity during the growth of S. enterica on 1,2-propanediol [3].

High impact information on propanal

• Messenger RNA levels correlated well with hALDH-1 protein levels and enzyme activities (1.5-13.6 milliunits/mg with propionaldehyde/NAD+ substrate, compared to < 1 milliunit/mg in controls) in individual clonal transfectant lines, and slot blot analysis confirmed the presence of the transfected cDNA [4].
• The dehydrogenase activity of the mitochondrial isozyme (E2) of human liver aldehyde dehydrogenase was stimulated about 2-fold by the presence of low concentrations (about 120-140 microM) of Mg2+ in the assay at pH 7.0 using propionaldehyde as substrate [5].
• To investigate the role of this enzyme in GTN tolerance, cumulative GTN concentration-response curves were obtained for both GTN-tolerant and -nontolerant rat aortic rings treated with the ALDH inhibitor cyanamide or the ALDH substrate propionaldehyde [6].
• This work describes a novel approach for the analysis of selected aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and acrolein) and acetone in environmental samples using micellar electrokinetic chromatography (MEKC) [7].
• Conversely, purified rabbit 2E1 exhibited K(m) and V(max) values for depropylation of 52 microM and 13.4 nmol propionaldehyde/min/nmol P450, respectively [8].

Chemical compound and disease context of propanal

• From studies involving 31 cataracts classified by the CCRG system and eight normal human lenses, it has been found that the adult human lens contains an enzyme system capable of oxidizing 1-2 mumol of glyceraldehyde, acetaldehyde, propionaldehyde, formaldehyde, and malonaldialdehyde per hour to their carboxylic acid form [9].
• The purified MDH has an optimum activity at pH 9.0 and at 45 degrees C. MDH of Methylocystis sp. GB 25 oxidises only primary alcohols from methanol to heptanol and aldehydes from formaldehyde to propionaldehyde and the glutaraldehyde, respectively [10].
• The hemolysis of human red cells in the presence of chlorpromazine and 2-methylpropanal, or propanal, has been studied by a spectrophotometric method [11].

Biological context of propanal

• Treatment with cyanamide or propionaldehyde did not significantly inhibit 1,1-diethyl-2-hydroxy-2-nitrosohydrazine-mediated vasodilation in tolerant or nontolerant aorta, indicating that these ALDH inhibitors do not affect the downstream effectors of NO-induced vasodilation [6].
• Steady-state and pre-steady-state kinetics of propionaldehyde oxidation by sheep liver cytosolic aldehyde dehydrogenase at pH 5.2. Evidence that the release of NADH remains rate-limiting in the enzyme mechanism at acid pH values [12].
• Propionaldehyde dehydrogenase activity is eliminated by mutations in any of the four identified complementation groups, suggesting that this activity may require a complex of proteins encoded by the operon [13].
• 5. At pH 7.40 and 37 degrees the following half-lives of hydrolysis for the various ephedrine oxazolidines were found: 5 sec (formaldehyde), 18 sec (propionaldehyde), 5 min (benzaldehyde), 5 sec (salicylaldehyde), 30 min (pivalaldehyde), 4 min (acetone), and 6 min (cyclohexanone) [14].
• Substrate specificity studies showed that aldose reductase, besides catalyzing the reduction of various aldehydes such as propionaldehyde, pyridine-3-aldehyde and glyceraldehyde, utilizes aldo-sugars such as glucose and galactose [15].

Anatomical context of propanal

• The rate of oxidation of N-butyl-N-(3-formylpropyl)nitrosamine by isozymes in rat liver cytosol was 2-2.5 times that found for propionaldehyde [16].
• To examine further structural requirements for inhibition, we tested a series of 4-(N,N-dialkylamino)benzaldehyde analogs as inhibitors of propanal oxidation by mouse liver and human erythrocyte class I ALDH [17].
• For the six rat strains, at millimolar propionaldehyde concentrations, NAD-dependent ALDH activity was associated primarily with mitochondria (51%) and microsomes (30%) [18].
• Transformation of menthofuran (II) by microsomes in the presence of NADPH yielded a metabolite identified as 2-Z-(2'-keto-4'-methyl cyclohexylidene) propanal (VI, pulegone-8-aldehyde) [19].
• The levels of activity with 68 microM propionaldehyde were significantly higher in cerebellum and putamen [20].

Associations of propanal with other chemical compounds

• The kinetic properties of highly purified preparations of sheep liver cytoplasmic aldehyde dehydrogenase (preparations that had been shown to be free from contamination with the corresponding mitochondrial enzyme) were investigated with both propionaldehyde and butyraldehyde as substrates [21].
• Pyrophosphate ions activate the steady-state rate of oxidation of propionaldehyde by sheep liver cytosolic aldehyde dehydrogenase at alkaline pH values [22].
• When further NADH binds to E-X-CO-NMe2 its fluorescence is enhanced over 4 times more than when it binds to unmodified enzyme; this fluorescence is completely unaffected by high propionaldehyde concentration and only slightly affected by p-nitrobenzaldehyde [23].
• Isopycnic centrifugation of tubule-derived postnuclear supernates in linear sucrose gradients resulted in propionaldehyde (5 mM)-driven ALDH activity being distributed in a manner consistent with both a mitochondrial and cytosolic localization [24].
• An in vitro ALDH assay indicated that ALDH2b possesses an NAD(+)-linked activity for oxidation of acetaldehyde, glycolaldehyde and propionaldehyde [25].

Gene context of propanal

• The ALDH III isozymes accounted for more than 80% of the total ALDH activities in gastric mucosa and exhibited Km values in the millimolar range for propionaldehyde at pH 9 [26].
• Consistent with this hypothesis, the inhibitory effects of acetaldehyde and propionaldehyde on the growth of this polA mutant were demonstrated [27].
• The kcat value for the oxidation of propionaldehyde by sheep liver cytosolic aldehyde dehydrogenase increased 3-fold, from 0.16 s-1 at pH 7.6 to 0.49 s-1 at pH 5.2, in parallel with the increase in the rate of displacement of NADH from binary enzyme.NADH complexes [12].
• Reduction of glutathionyl propanal [gammaGlu-Cys(propanal)-Gly] was more efficient than that of Gly-Cys(propanal)-Gly and gamma-aminobutyric acid-Cys(propanal)-Gly suggesting a possible interaction between alpha-carboxyl of the conjugate and AR [28].
• However, subsequent analysis of hALDH2 activity toward propionaldehyde revealed that both 4ONE and the oxidation product, 4ONEA, were potent, irreversible inhibitors of the enzyme [29].

Analytical, diagnostic and therapeutic context of propanal

• Microgram per m(3) (sub-ppb) levels of the aliphatic aldehydes, propanal, 1-butanal, 1-heptanal, and 1-hexanal, in ambient air were successfully determined by HPLC separation with fluorometric detection [30].
• Forearm cutaneous blood flow was monitored continuously by laser Doppler velocimetry in 12 normal human subjects before and after a 5-min topical challenge with 5 M propionaldehyde [31].

References