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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.
Mol Cell Biol 1985 May
PMID:Isolation of alcohol oxidase and two other methanol regulatable genes from the yeast Pichia pastoris. 388 90

A mathematical model of the growth of the cell culture was developed. The model takes into account changes of the levels of the enzymes which define the metabolism rate, transport of the substrate into the cell, regeneration of the donors of energy. The model is based on the proposition that the rate of overall protein synthesis in the cell is defined by the concentration of a few aminoacids limiting the growth. The chemostat culture of the methanol-assimilating yeast was used as the object of modelling. The model allows to explain the experimental kinetics of alterations in cell number (biomass) and other measurable characteristics of the culture during the transient process when the dilution rate was changed.
Mol Biol (Mosk)
PMID:[Mathematical model of transitional processes in the chemostat culture of microorganisms]. 389 32

In the presence of methanol 50S ribosomal subunits reveal two independents sites for binding of deacylated tRNA and/or AcPhe-tRNA. The site with lower affinity was identified with the donor (P') site as the dissociation constant (Ka) for AcPhe-tRNA was equal to the Michaelis constant for its reaction with puromycin both at 0 degrees C and 25 degrees C. Log Ka increases linearly with methanol concentration. This suggests that there are no conformational transitions of the interacting components, the affinity increases only quantatively due to lowering of the dielectric constant of water, and the site can exist even in the absence of methanol, but its Ka may be too low to be measured. It follows from these data that the higher-affinity site, which is observed both in the absence and presence of methanol, cannot be the P' site as it was generally believed. By all its properties it is more like the additional E site, which has been recently found on 70S ribosomes. Specifically, its affinity for deacylated tRNA is about 1000-fold higher than for AcPhe-tRNA (in the P'-site they are almost the same).
Mol Biol (Mosk)
PMID:[Deacylated tRNA binds with 50S subunits of Escherichia coli ribosomes at a special site not corresponding to the P'-site]. 390 11

We have examined a water-dominated multicomponent system after irradiation in the multimegarad dose range with gamma rays from a 60Co source at both 77 and 310 K. The constituents were simple organic compounds in the proportions in which they appear in a dense interstellar cloud: HCN/CH3OH/CH3CN/C2H5CN/HCOOH = 1:0.6:0.2:0.1:0.05. The total amounts were adjusted to correspond to a carbon to nitrogen ratio of 1.8 and a water content of about 50% in a cometary nucleus where the dust to volatiles ratio is 1; the total amount of CN-bearing compounds was taken to correspond to 0.4% of the cometary mass. In experiments at 310 K about 40 radiolytic products are identified, among them aldehydes and amino and carboxylic acids. Abundant polymeric material (Mw up to 80,000 daltons) is formed. The basic aspects of radiolysis of the liquid system are present also at 77 K, although at radiation-chemical yields that are lower by one to two orders of magnitude. We have considered the relevance of the present findings to the chemistry of a liquid-water core and the icy layers of a cometary nucleus.
J Mol Evol 1985
PMID:Radiation chemistry of a multicomponent aqueous system relevant to chemistry of cometary nuclei. 393 96

The activity of the human erythrocyte acid phosphatase is modulated by a series of structural analogs of purine. The unsubstituted purine base does not affect the enzyme activity. Addition of a substituent at the number six position usually generates an analog which activates the enzyme while similar substitutions at the two position usually generate an inhibitor. Pyrimidines are generally ineffective as modulators while several modifications of the imidazole ring of the purine analogs do not abolish the modulator activity of the purine analog. The level of response to all active analogs is isozyme specific. Differences in apparent relative affinities among the modulators are noted. The modulators with a positive effect on enzyme activity, are effective in the presence of methanol which is more effective than H2O as a phosphate acceptor. These analogs act by enhancing the rate of transfer of phosphate to H2O, while decreasing the rate of transfer to methanol. The results suggest that the purine analogs may act by altering the rate of hydrolysis of the phosphoenzyme intermediate by H2O or may change the rate-limiting step in the catalytic mechanism.
Mol Cell Biochem 1985 Mar
PMID:Studies of the purine analog associated modulation of human erythrocyte acid phosphatase activity. 398 4

Promastigotes of Leishmania adleri were submitted to an extraction procedure providing different carbohydrate-containing extracts. The purified aqueous extract showed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis a complex peptide pattern but carbohydrate was present only in bands of Mr approximately equal to 45 000-50 000 and 13 500. Methylated derivatives of the hexose components in this extract, analysed by mass spectrometry, suggest the presence of short sugar chains of alpha-D-mannopyranose and a branched alpha-D-mannan. The phenol extract, released in the aqueous layer a chloroform/methanol/water soluble complex contained 25% protein, 17% phosphate, 11% glucosamine, uronic acid and 61% neutral carbohydrate, and a chloroform/methanol/water insoluble fraction consisting of a glycoprotein Mr approximately equal to 22 000 and a proteic doublet Mr approximately equal to 58 000-66 000. A polysaccharide, showing galactose as predominant sugar, was released through alkaline extraction corresponding to a branched, mainly 1----3 linked galactan associated with alpha-D-mannopyranosyl units.
Mol Biochem Parasitol 1985 Jan
PMID:Partial chemical characterization of the carbohydrate moieties in Leishmania adleri glycoconjugates. 398 51

After contact with human serum, a series of proteins become exposed on the surface membranes of schistosomula of Schistosoma mansoni as revealed by radioiodination of the intact parasites. Among the proteins, a doublet (Mr 45 000) is particularly prominent. These doublet proteins, which are believed to be parasite-derived, become apparent after a very short time of incubation with human serum (10 min or less) and are expressed on the surface membranes after contact with a high molecular weight component of human serum (Mr greater than 80 000). Pretreatment of the parasites with 1.25 mM colchicine or fixation with 2% glutaraldehyde does not prevent the serum-induced expression of the doublet proteins. Extraction of the parasites with chloroform:methanol 2:1 (v/v), however, blocks the human serum effect. Affinity chromatography using immobilized low density lipoproteins (LDL) from human serum shows a tight binding between the 125I-labelled 45 kDa doublet to the LDL. The possible role of the 45 kDa doublet as a receptor for LDL is discussed.
Mol Biochem Parasitol 1985 Jan
PMID:The interaction of human serum with the surface membrane of schistosomula of Schistosoma mansoni. 398 52

Fatty acid composition of human heart phospholipids was determined in 53 specimens of left ventricular myocardium collected during mitral valve replacement. Ages of the subjects (29 males and 24 females) ranged from 14 to 75 years (mean age = 54). Samples were immediately placed in chloroform-methanol 2/1, v/v to which antioxidant was added. Extracted phospholipids were converted to methyl esters which were analyzed by gas liquid chromatography on glass capillary columns. Morphological examination was also performed on 35 out of 53 samples. Age of the patients as well as the morphological state of the organ had no significant effect on major fatty acids in heart phospholipids. No difference by sex was detected. Trans-octadecenoic isomers were detected in all samples but they remained at a low level (0.4% to 1.2% of the total fatty acids).
J Mol Cell Cardiol 1985 Aug
PMID:Fatty acid composition of human heart phospholipids: data from 53 biopsy specimens. 404 43

Dynamic systems, modelling the elementary act of nucleophilic attack on the carbonyl carbon atom of amide (N-methyl-acetamide) and ester (methylacetate) substrates by some compounds, simulating the nucleophilic group of various types proteases active site were calculated and analysed by the CNDO/2 method, namely: 1) methoxyanion and the methanol (serine proteases), 2) water molecule in the presence of formate anion (carboxylic proteases) and 3) mercaptide anion (CH3S-) (thiolic proteases). The formation of productive enzyme-substrate complex was shown not only to orient reactive groups of the enzyme and substrate, but also to activate it by induction of a certain degree of cleavable pyramidalization, as a result of the partial resonance stabilization energy loss.
Mol Biol (Mosk)
PMID:[Quantum chemistry analysis of the mechanism of action of proteolytic enzymes. II. Nucleophilic attack]. 609 13

A physical map for plasmid R1162 (Sm, Su, IncP4) was constructed. Neither EcoRI, PstI nor EcaI cut within a region essential for replication, molbilization or streptomycin resistence. Plasmid R1162 can replicate in E. coli as well as in Pseudomonas species and shows a strong dependence for DNA polymerase I in E. coli. By RP4 induced mobilization, R1162 can be transferred from E. coli to Pseudomonas AM1. A hybrid plasmid pFG7 (MW=8.4 x 10(6), Sm, Su, Ap, Tc) was constructed between pBR322 and R1162, which allows the selection of hybrid plasmids by insertional inactivation with the restriction enzymes HindIII, BamHI, SalI, ClaI. Transformation of E. coli SK1592 with Ecal-cut and ligated R1162-DNA and Pseudomonas AMI-DNA and subsequent mobilization of the hybrid plasmids into Pseudomonas AM1/M15a (methanol dehydrogenase-) led to the isolation of Pseudomonas AM1/M15a colonies, which could grow on methanol again. Back-conjugation into E. coli SK1592, subsequent mobilization studies and plasmid analysis suggests that the gene for Pseudomonas methanol dehydrogenase has been cloned in this vector.
Mol Gen Genet 1980
PMID:The use of plasmid R1162 and derivatives for gene cloning in the methanol-utilizing Pseudomonas AM1. 624 28


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