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)

An alpha-amylase gene (aml) of Streptomyces limosus ATCC 19778 was cloned in Streptomyces lividans 66. S1 mapping experiments identified an aml transcript 1.8 kb in length and the extracellular enzyme was estimated to be 59 kD in size, suggesting that aml was transcribed as a monocistronic mRNA species. Expression of the gene was induced by maltose (or maltodextrins) in S. limosus and when aml was cloned in S. lividans or Streptomyces coelicolor A3(2). In S. limosus, mannitol repressed aml expression while glucose had little or no effect; in S. lividans and S. coelicolor the relative effects of the two sugars were reversed. Both induction and carbon-source repression of aml expression appeared to occur at the level of transcriptional initiation. Glucose repression in S. coelicolor was dependent upon a functional glucose kinase gene.
Mol Microbiol 1988 Mar
PMID:Cloning, characterization and regulation of an alpha-amylase gene from Streptomyces limosus. 326 2

The complete three-dimensional structure of the alpha-amylase inhibitor Tendamistat in aqueous solution was determined by 1H nuclear magnetic resonance and distance geometry calculations using the program DISMAN. Compared to an earlier, preliminary determination of the polypeptide backbone conformation, stereo-specific assignments were obtained for 41 of the 89 prochiral groups in the protein, and a much more extensive set of experimental constraints was collected, including 842 distance constraints from nuclear Overhauser effects and over 100 supplementary constraints from spin-spin coupling constants and the identification of intramolecular hydrogen bonds. The complete protein molecule, including the amino acid side-chains is characterized by a group of nine structures corresponding to the results of the nine DISMAN calculations with minimal residual error functions. The average of the pairwise minimal root-mean-square distances among these nine structures is 0.85 A for the polypeptide backbone, and 1.52 A for all the heavy atoms. The procedures used for the structure determination are described and a detailed analysis is presented of correlations between the experimental input data and the precision of the structure determination.
J Mol Biol 1988 Dec 05
PMID:Determination of the complete three-dimensional structure of the alpha-amylase inhibitor tendamistat in aqueous solution by nuclear magnetic resonance and distance geometry. 326 33

Escherichia coli Lon-mutants deficient in intracellular protease La have been isolated. The rate of degradation of normal cellular proteins was 1.5-2-fold lower in Lon-mutants as compared with that of the wild type strain. The rate of degradation of canavanine-containing abnormal proteins, as well as foreign proteins was significantly higher in E. coli than that of normal proteins. Lon-mutants possessed 2-2.5-fold lower rates of degradation of abnormal proteins as compared with Lon+-strains. The rate of degradation of human interferon alpha-2 was 10-fold higher in E. coli than that of abnormal proteins. B. amyloliquefaciens alpha-amylase degraded in E. coli with the rate comparable with that of abnormal proteins, since chloramphenicolacetyltransferase from Tn9 was stable in E. coli. The rate of degradation of interferon alpha-2 was 2-fold lower in Lon-mutants (half-life 23-26 min) than in the initial strain (11-12 min). Lon-mutants were effectively used as recipient strains for constructing strains-producers of several human alpha- and beta-interferons.
Mol Biol (Mosk)
PMID:[Stability of normal, abnormal and recombinant proteins in Escherichia coli strains deficient for intracellular proteinase La--the product of the lon gene]. 328 35

This is a preliminary report on the determination of the solution conformation of the alpha-amylase inhibitor Tendamistat by nuclear magnetic resonance and distance geometry calculations. A characterization is given of the complete polypeptide backbone fold and the side-chains of the presumed active site in this protein. These results are based on complete sequence-specific resonance assignments, a list of 401 distance constraints from nuclear Overhauser effects, 168 distance constraints from hydrogen bonds and disulphide bridges, and 50 torsion angle constraints from measurements of spin-spin coupling constants.
J Mol Biol 1986 May 20
PMID:Studies by 1H nuclear magnetic resonance and distance geometry of the solution conformation of the alpha-amylase inhibitor tendamistat. 348 3

The crystal and molecular structure of the alpha-amylase inhibitor Hoe-467A has been determined and refined at high resolution. The polypeptide chain is folded in two triple-stranded sheets, which form a barrel. The topology of folding is as found in the immunoglobulin domains. The amino acid triplet Trp18-Arg19-Tyr20 has an exceptional conformation and position in the molecule and is possibly involved in inhibitory activity.
J Mol Biol 1986 May 20
PMID:Crystal structure determination, refinement and the molecular model of the alpha-amylase inhibitor Hoe-467A. 348 4

Endogenous alpha-amylase inhibitor from wheat has been crystallized by a microdialysis method. There are two forms of monoclinic crystal in a microdialysis cell with a space group of P2(1). The unit cell dimensions are a = 43.5 A, b = 64.8 A, c = 32.2 A, beta = 113 degrees for the rod-like crystal, and a = 42.5 A, b = 65.2 A, c = 32.2 A, beta = 112 degrees for the plate-like crystal. The former is suitable for structure analysis because it gives the sharp diffraction beyond 2.0 A resolution, and the latter tends to form a twin crystal. A heavy-atom derivative has been successfully prepared with the heavy-atom reagent K2PtCl4, and structure analysis is in progress.
J Mol Biol 1987 Feb 20
PMID:Crystallographic study of endogenous alpha-amylase inhibitor from wheat. 349 78

Modification of liquefying alpha-amylase by diethylpyrocarbonate or its photo-oxidation in the presence of rose bengal caused rapid loss of enzyme activity. The photo-oxidation followed pseudo-first-order kinetics giving maximal value at pH 8.0. The photo-oxidized enzyme showed a characteristic increase in absorbance at 250 nm which was directly proportional to the extent of inactivation. Diethylpyrocarbonate at low concentration at pH 6.0 and 30 degrees C completely inactivated alpha-amylase. Inactivation followed pseudo-first-order kinetics. The reaction order with respect to inactivation by diethylpyrocarbonate-modified enzyme showed increased absorbance at 240 nm which was reversed completely upon treatment with NH2OH at 30 degrees C for 16 hr. Calculating the histidine residues being modified from the increase in absorbance at 240 nm showed that three residues were ethoxyformylated on treatment with diethylpyrocarbonate, of which only one was found at the active site. Substrate and competitive inhibitor protects the enzyme against both, photo-oxidation, and modification by diethylpyrocarbonate, confirming that histidine plays an essential role at the alpha-amylase active site.
Mol Cell Biochem 1985 Feb
PMID:Active site studies on Bacillus amyloliquefaciens alpha-amylase (I). 387 8

Three types of Amy-2-related DNA sequences, Amy-2a I, Amy-2a II and Amy-X, exist in the genome of mice of the inbred strain A/J. Amy-2a I and Amy-X are single copy sequences. Amy-2a II occurs as three copies per haploid genome. DNA sequence analysis reveals that both classes of Amy-2a genes specify the same unique pancreatic alpha-amylase mRNA species, since they share common exon sequences. Four independently cloned Amy-2a II isolates were found to be identical in all regions sequenced. This suggests that most, if not all, chromosomal Amy-2a II copies are identical. Amy-X is presumably a pseudogene, since its exon sequences, which are distinct from those of Amy-2a, are not detected in pancreatic alpha-amylase mRNA. We have determined the transcriptional activities of the Amy-2a genes by mapping in vitro elongated nascent transcripts to Amy-2a restriction fragments. Transcription initiation occurs at or close to the cap site. The expression of Amy-2a in vivo is under control of strong promoters, which are active exclusively in the pancreas. The accumulation of alpha-amylase mRNA in cells of the exocrine pancreas is regulated mainly at the transcriptional level. We have searched for pancreatic transcripts of Amy-1a, which specifies both parotid gland and liver-type alpha-amylase mRNAs. Surprisingly, the weak Amy-1a promoter, which directs the synthesis of the mRNA containing the liver-type leader sequence, also is active in the pancreas and, hence, in all alpha-amylase-producing tissues.
J Mol Biol 1985 Sep 20
PMID:Expression of mouse Amy-2a alpha-amylase genes is regulated by strong pancreas-specific promoters. 387 71

The major storage proteins (prolamins) of barley, rye and wheat are characterized by the presence of two or more unrelated structural domains, one of which contains repeated sequences. Because of this repetitive structure and their restricted distribution (only in grasses), it has been suggested that the prolamins are of recent origin. Contrary to this hypothesis, we show that parts of the non-repetitive domain of one group of prolamins are homologous with sequences present in a large group of seed proteins from monocotyledonous and dicotyledonous plants; including Bowman-Birk protease inhibitors, cereal inhibitors of alpha-amylase and trypsin, and 2 S globulin storage proteins of castor bean and oil seed rape. This implies an ancient origin for these non-repetitive domains. The origins of the repetitive domains are not known but may lie within the grasses.
J Mol Biol 1985 Jun 05
PMID:Molecular evolution of the seed storage proteins of barley, rye and wheat. 402 Aug 67

The effect of gonadectomy (at the 10th day of life) and treatment with sexual steroids (during the first month) upon development of alpha-amylase activity in rat parotid gland has been studied. Alpha-amylase specific activity of parotid glands from 20-day-old orchidectomized rats and from 25-day-old ovariectomized animals was significantly higher than that of intact male and female rats of the same age respectively. Spayed males treated with testosterone (10 microgram/day on the 13th, 15th, and 17th day) and ovariectomized rats treated with oestradiol (2.5 microgram/day from the 16th to the 22nd day) showed values of enzymic activity similar to those of normal animals. Results indicate that oestradiol and testosterone have an inhibitory effect upon the increase of alpha-amylase activity in parotid gland during a very defined period of development.
Mol Cell Biochem 1982 Apr 30
PMID:Effect of sexual steroids upon ontogeny of alpha-amylase of rat parotid gland. 617 53


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