Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of the key enzymes of ribulose monophosphate cycle for formaldehyde oxidation and assimilation were tested in crude extracts from temperature sensitive mutants of obligatemethylotroph M. flagellatum KT. Two mutants deficient in phosphoglucoisomerase activity were identified during this screening. Phosphoglucoisomerase of T525 pgi-1 mutant was active both at permissive (30 degrees C) and nonpermissive (42 degrees C) temperatures. Complete inactivation of the enzyme at 42 degrees C occurred in 2 h in vitro, while in vivo incubation at nonpermissive temperature for more than 10 h was required for the enzyme inactivation. Phosphoglucoisomerase activity of T566 pgi-2 was 5-fold lower as compared with the one from the parent strain incubated at 30 degrees C. The enzyme was inactivated in 2 min. in crude extract at nonpermissive temperature.
Mol Gen Mikrobiol Virusol 1987 Aug
PMID:[Characteristics of Methylobacillus flagellatum KT mutants, deficient for phosphoglucoisomerase, an enzyme of the ribulose monophosphate cycle of obligate methylotrophic bacteria]. 311 97

The hyperresistance to 4-nitroquinoline-N-oxide (4-NQO) and formaldehyde (FA) of yeast strains transformed with the multi-copy plasmids pAR172 and pAR184, respectively, is due to the two genes, SNQ and SFA, which are present on these plasmids. Restriction analysis revealed the maximal size of SFA as 2.7 kb and of SNQ as 2.2 kb, including transcription control elements. The presence of the smallest 2.7 kb subclone carrying SFA increased hyperresistance to formaldehyde fivefold over that of the original pAR184 isolate. No such increase in hyperresistance to 4-NQO was seen with the smaller subclones of the pAR172 isolate. Disruption of the SFA gene led to a threefold increase in sensitivity to FA as compared with the wild type. Expression of gene SNQ introduced on a multi-copy vector into haploid yeast mutants rad2, rad3, and snm1 did not complement these mutations that block excision repair.
Mol Gen Genet 1988 Feb
PMID:Genetic characterization of hyperresistance to formaldehyde and 4-nitroquinoline-N-oxide in the yeast Saccharomyces cerevisiae. 312 60

It was the aim of this study to test the hypothesis that abnormal thickening of capillary basal laminae in the diabetic organism may be due to postulated cycles of capillary cell turnover of increasing frequency. The accelerated cell turnover, it was theorized, may lead to laminar thickening through adhesion of basal laminae synthesized by regenerating cells with residual laminae of previously degenerated capillaries. Nine streptozotocin-diabetic rats and six nondiabetic controls were injected ip with tritiated thymidine, 1.0 microCi/g body weight. Three additional controls, for the purpose of identifying a potentially toxic action of streptozotocin which may affect the incorporation of thymidine into DNA, were treated in an identical manner. One hour postinjection, the animals were sacrificed, the heart was excised and sliced transversely. The tissue slices were fixed in 10% neutral buffered Formalin, dehydrated, and embedded in paraffin. Sections 6 microns thick were dipped in Kodak emulsion and were developed following an exposure of 4 weeks. Examination of the autoradiographs revealed distinctly labeled capillary endothelial cells in the myocardium of nondiabetic controls; labeling of these cells was strikingly reduced in the diabetic rats. These results indicate that proliferative activity of capillary endothelial cells is markedly retarded in the diabetic myocardium and that the reduced labeling can be ascribed genuinely to the diabetic environment. This finding does not provide support for the hypothesis that an accelerated cell turnover may be responsible for basal laminar thickening in the diabetic.
Exp Mol Pathol 1985 Aug
PMID:Incorporation of [3H]thymidine into myocardial capillary cells in streptozotocin-diabetic rats. 315 94

In order to provide data for meaningful interpretation and quantitation of immunogold labeling on cryosections their morphology and permeability to protein A-gold were evaluated: We studied plastic sections of immunogold-labeled ultrathin and semithick cryosections cut perpendicular to the original cryosection plane. Various soluble and insoluble antigens in different specimens (hemoglobin and histone H5 in chicken erythrocytes, tubulin in Leishmania cells, and outer membrane protein OmpA in Escherichia coli) were fixed with glutaraldehyde-formaldehyde, formaldehyde, or periodate-lysine-paraformaldehyde and incubated with specific antibodies and protein A-gold of different sizes. The cryosection surface may be rough or smooth depending both on the sectioned material and on dehydration and drying artifacts or possibly on the cutting process itself. Well-preserved sections are capable of withstanding considerable deformation without showing clefts or cracks. If the sectioned specimen is sufficiently fixed, protein A-gold is not able to enter the IgG-labeled sections significantly but follows surface irregularities. However, gold particles can be detected within visibly damaged sections.
J Ultrastruct Mol Struct Res
PMID:Transverse sectioning of plastic-embedded immunolabeled cryosections: morphology and permeability to protein A-colloidal gold complexes. 333 Sep 84

A brominated poly[d(G-C)].poly[d(G-C)] which forms a stable Z-DNA helix under physiological salt conditions was prepared. The rabbits were immunized with the brominated polynucleotide complexed with methylated bovine serum albumin. Antisera that are highly specific to the Z-DNA were produced: there is practically no interaction between the antisera and the native or denaturated DNA and the B-form of poly[d(G-C)].poly[d(G-C)]. This makes possible their use as reagents for determining the presence of Z-DNA in biological systems. A sensitive enzyme-linked immunosorbent assay (ELISA) that permits detection of 5 ng/ml Z-DNA was developed. This method was used for studying the B-Z transition and for antigenic determinant characterization. It was established, that formaldehyde amino-derivatives interact with the antigenic determinant and prevent the immunochemical assay of Z-DNA. The H1 and H3 histones prevent and and spermine increases the interaction of Z-DNA with antibodies.
Mol Biol (Mosk)
PMID:[Enzyme immunologic method for the study of left-handed DNA]. 344 47

Multiple reactions are thought to be involved in transforming dialkynitrosamines to active carcinogens. The first proposed step is enzymatic alpha-hydroxylation by the active oxygen species of cytochrome P-450, followed by nonenzymatic N-dealkylation and formation of diazohydroxides (RNNOH). The latter transformation can reasonably occur by a two-step mechanism via tautomerization of a monoalkylnitrosamine intermediate or directly from the alpha-hydroxylated species in one step. Both of these pathways in the transformation of hydroxymethylnitrosamine to diazohydroxide and formaldehyde were examined by the semiempirical molecular orbital method MNDO (modified neglect of diatomic differential overlap) and the ab initio method using STO-3G and 3-21G basis sets. Complete geometry optimizations of all reactants, intermediates, transition states, and products were performed. MNDO was also used to compare the similar transformation of the dimethyl analog. Both methods show that in the gas phase a concerted pathway involving a six-membered ring transition-state pathway is kinetically favored over a two-step pathway involving N-demethylation followed by tautomerization via two four-membered ring transition states. This reaction appears to be a viable one to formation of an ultimate carcinogen by parent dialkylnitrosamines in the hydrophobic substrate binding site of cytochrome P-450.
Mol Toxicol
PMID:Nitrosamine carcinogen activation pathway determined by quantum chemical methods. 344 50

The lipid-soluble folate antagonist, 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido[2,3-d]pyrimidin e (piritrexim; BW301U), induced misincorporation of dUMP in human B (SB)- and T (MOLT-4)-lymphoblastoid cells, and in human promyelocytic leukemia cells (HL-60). Analysis by alkaline sucrose gradients and alkaline elution indicated that 3H-DNA that had been labeled for 15 min distributed into progressively smaller DNA fragment sizes in a drug concentration-dependent manner from 0 microM to 50 microM piritrexim. This phenomenon was observed regardless of the labeled nucleotide precursor employed for detection of newly synthesized DNA [( 3H]deoxyuridine, [3H]deoxyadenosine, or [3H]deoxycytidine). In contrast, formaldehyde denaturation and sedimentation of DNA in neutral denaturing sucrose gradients released only 3-4% of the newly synthesized DNA as 3S-6S fragments (80-200 nucleotides), whereas the remaining population of newly synthesized DNA pelleted to the bottom of the tube. Failure to detect DNA fragmentation under neutral conditions to the extent observed under alkaline conditions indicated the presence of apurinic and apyrimidinic sites in DNA--lesions which would be expected in DNA undergoing excision-repair of misincorporated dUMP. Cytotoxicity resulting from dUMP misincorporation was consistent with the enhanced toxicity of piritrexim which was observed when HL-60 cells or MOLT-4 cells were exposed concurrently to exogenous deoxyuridine. Deoxyuridine-enhanced toxicity was demonstrated to be concentration dependent for both cell lines when piritrexim concentrations were marginally toxic. The cytotoxic effect of dUMP misincorporation was further substantiated by the observation that MOLT-4 cells treated with 0.5 microM piritrexim alone eventually developed resistance to the drug, whereas treatment with both piritrexim and 10 microM deoxyuridine prevented the selection of piritrexim-resistant cells.
Mol Pharmacol 1986 Dec
PMID:Drug concentration-dependent DNA lesions are induced by the lipid-soluble antifolate, piritrexim (BW301U). 349 Dec 87

To investigate the molecular basis for the pattern of ovarian steroid production during the bovine estrous cycle, the relative levels of mRNA specific for cholesterol side-chain cleavage cytochrome P-450, 17 alpha-hydroxylase cytochrome P-450, adrenodoxin, and low density lipoprotein receptor were determined in ovarian antral follicles of differing size (less than 3-18 mm) and corpora lutea from the early, early-mid, late-mid, and regressionary stages. Total and poly(A)+ RNA was size-fractionated on agarose-formaldehyde gels, transferred to nylon filters and hybridized to specific 32P-labeled probes. The levels of mRNAs for the rate-limiting enzymes in the conversion of cholesterol into progesterone, namely cholesterol side-chain cleavage cytochrome P-450 and its electron donor, adrenodoxin, were higher in corpora lutea than in follicles. Conversely the levels of mRNA specific for the key regulatory enzyme in the conversion of pregnenolone or progesterone to androgen, namely 17 alpha-hydroxylase cytochrome P-450, were high in all antral follicles examined but were low in young corpora lutea and undetectable in more mature corpora lutea. Low density lipoprotein receptor mRNA was detectable in antral follicles and corpora lutea but the levels were greater in corpora lutea. These results suggest that the pattern of changes in steroid hormone biosynthesis during the bovine estrous cycle and in the ovarian content of steroidogenic enzymes is related to and probably dependent upon the pattern of change in levels of mRNAs for steroidogenic enzymes and related proteins.
Mol Endocrinol 1987 Mar
PMID:Levels of messenger ribonucleic acid encoding cholesterol side-chain cleavage cytochrome P-450, 17 alpha-hydroxylase cytochrome P-450, adrenodoxin, and low density lipoprotein receptor in bovine follicles and corpora lutea throughout the ovarian cycle. 350 8

The presence of plasmid pKM101 in Escherichia coli cells results in a slight increase in their sensitivity of lethal effect of formaldehyde. Plasmid ability to sensitize bacterial cells to formaldehyde inactivation is controlled by some chromosomal (uvrE, uvrA, recA) and plasmid-borne (mucAB) genes and depends on SOS-DNA repair activity. Plasmid pKM101 is capable of decreasing the level of repair reliability of DNA damaged by formaldehyde thus causing increased bacterial sensitivity to this agent.
Mol Gen Mikrobiol Virusol 1986 May
PMID:[Lethal effect of formaldehyde on Escherichia coli strains carrying or lacking the plasmid pKM101]. 354 Jun 39

We have quantified using flow cytometry foam cells of aortas from normolipidemic swine varying in age from 6 months to 12 years. These swine were maintained throughout their lives on a low-fat, cholesterol-free diet. Intimal-medial tissues removed from the swine aortas were enzymatically dissociated to prepare Formalin-fixed cell suspensions. Foam cells were labeled by specific staining of their intracellular cholesteryl ester using the fluorescent dye filipin. This was carried out by first removing cellular unesterified cholesterol with ethanol, then enzymatically hydrolyzing cellular cholesteryl ester, and finally staining with filipin the unesterified cholesterol derived from hydrolysis of cholesteryl ester. Results of flow cytometric analysis indicated that thoracic foam cell densities of female swine became more variable and tended to increase with age. It appeared that there were two subgroups of female swine with either high or low levels of thoracic foam cells. A similar finding was not observed for abdominal foam cells in female swine nor for thoracic or abdominal foam cells in the smaller number of older male swine. Abdominal foam cell densities in younger males, however, also appeared to be comprised of low and high foam cell groups. Foam cell densities did not correlate with serum cholesterol or triglyceride levels. However, a genetic basis for some of the variability in foam cell densities among these animals was suggested by the observation that females with high thoracic foam cell densities had greater commonality among ancestors than did females with low thoracic foam cell densities.
Exp Mol Pathol 1987 Feb
PMID:Flow cytometric quantification of cholesteryl ester-containing "foam" cells. I. Analysis of aortas from normolipidemic swine. 354 51


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