Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.11.18 (MAP)
 7,412 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Analytical ultracentrifugation of highly purified seminalplasmin revealed a molecular mass of 6300. Amino acid analysis of the protein preparation indicated the absence of sulfur-containing amino acids cysteine and methionine. The amino acid sequence of seminalplasmin was determined by manual Edman degradation of peptides obtained by proteolytic enzymes trypsin, chymotrypsin and thermolysin: NH(2)-Ser Asp Glu Lys Ala Ser Pro Asp Lys His His Arg Phe Ser Leu Ser Arg Tyr Ala Lys Leu Ala Asn Arg Leu Ser Lys Trp Ile Gly Asn Arg Gly Asn Arg Leu Ala Asn Pro Lys Leu Leu Glu Thr Phe Lys Ser Val-COOH. The number of amino acids according to the sequence were 48, the molecular mass 6385. As predicted from the sequence, seminalplasmin very likely contains two alpha-helical domains in which residues 8-17 and 40-48 are involved. No evidence for the existence of beta-sheet structures was obtained. Treatment of seminalplasmin with the above proteases as well as with amino peptidase M and carboxypeptidase Y completely eliminated biological activity.
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PMID:Amino acid sequence of seminalplasmin, an antimicrobial protein from bull semen. 1645 69

The phosphatidylethanolamine-binding protein (PEBP) family is widely distributed in various species, from bacteria to mammals. These proteins seem to modulate important cell mechanisms: they control heterotrimeric G-proteins, inhibit the MAP-kinase and NFkappaB signaling pathways, and also serine proteases (thrombin, neuropsin, and chymotrypsin). In order to establish structure-function relationships for this family of proteins, our study focuses on PEBPs expressed within a single organism: Drosophila melanogaster, which constitutes a model system that lends itself well to establishing links between genes' expression and the corresponding proteins' functions, and to studying physiological mechanisms such as development. Here, we describe an optimized protocol for high level over-expression and high yield/high purity production of CG18594, one of Drosophila six putative PEBPs, for biophysical studies. The yield of the purified 15N labeled protein is estimated to be 60 mg/L of M9 minimal medium. Analysis of the secondary structure using circular dichroism indicates that the protein comprises mainly beta-sheets at pH 7. The good dispersion of the crosspeaks on the 1H-15N HSQC spectrum provides evidence of a proper folding of the purified protein, though its time evolution suggests a tendency to denature. Taken together, these data are consistent with the assumption that the CG18594 protein belongs to the PEPB family.
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PMID:Cloning, high yield over-expression, purification, and characterization of CG18594, a new PEBP/RKIP family member from Drosophila melanogaster. 1652 46

The Arabidopsis MAP kinase 4 (MPK4) substrate MKS1 was expressed in Escherichia coli and purified, full-length, 6x histidine (His)-tagged MKS1 was phosphorylated in vitro by hemagglutinin (HA)-tagged MPK4 immuno-precipitated from plants. MKS1 phosphorylation was initially verified by electrophoresis and gel-staining with ProQ Diamond and the protein was digested by either trypsin or chymotrypsin for maximum sequence coverage to facilitate identification of phosphorylated positions. Prior to analysis by mass spectrometry, samples were either desalted, passed over TiO(2) or both for improved phosphopeptide detection. As MAP kinases generally phosphorylate serine or threonine followed by proline (Ser/Thr-Pro), theoretical masses of potentially phosphorylated peptides were calculated and mass spectrometric peaks matching these masses were fragmented and searched for a neutral-loss signal at approximately 98 Da indicative of phosphorylation. Additionally, mass spectrometric peaks present in the MPK4-treated MKS1, but not in the control peptide map of untreated MKS1, were fragmented. Fragmentation spectra were subjected to a MASCOT database search which identified three of the twelve Ser-Pro serine residues (Ser72, Ser108, Ser120) in the phosphorylated form.
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PMID:Phosphorylation sites of Arabidopsis MAP kinase substrate 1 (MKS1). 1770 78

Bioactive peptides with a variety of effects have been described from several nutritive proteins. They exhibit antimicrobial, blood-pressure lowering, antithrombotic, immunomodulatory, and cholesterol-modulating effects. In this study, we have examined whether peptides derived from food proteins might influence bile acid synthesis. A reporter gene cell line that carries a cholesterol 7alpha-hydroxylase promoter fragment fused to firefly luciferase ( cyp7a-luc) was used to screen for nutritive peptides affecting cyp7a expression, the enzyme catalyzing the rate-limiting step in bile acid synthesis. Proteolytic hydrolysates were prepared from soy protein and bovine casein with pepsin, trypsin, chymotrypsin, and elastase and size fractionated using ultrafiltration. Several bioactive hydrolysates could be identified that inhibited luciferase expression. Also, an activation of kinase (AKT, ERK, p38-MAPK) signaling could be observed. Selected hydrolysates were further fractionated by reversed-phase HPLC. Bioactive HPLC-fractions were obtained from casein but not from soy hydrolysates; however, activity could not be recovered in single peak fractions. Peptides in such fractions were identified by mass spectrometry. Five selected peptides from alpha S1-casein present in active fractions were synthesized, but none of these showed activity in the cyp7a-luc screening system. However, two of them activated MAP-kinase signaling similar to the hydrolysates, which suggests, that these peptides are involved in cyp7a regulation by the casein hydrolysates.
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PMID:Screening for nutritive peptides that modify cholesterol 7alpha-hydroxylase expression. 1854 26