Amino acid crystals

Pentyl 2-(1H-indole-2-carboxamido)benzoate (5) is obtained in good yield as stable crystals by reaction of pentyl 2-amino benzoate (6) with indole-2-carbonyl chloride acid (7) in the presence of pyridine. The crystal structure of 5 confirms the presence of intramolecular hydrogen bonding (N-H…O) which produces a six-membered ring, and the molecules are linked together by intermolecular hydrogen forces (N-H…O).

6p tocectocec 25-05-2020 9 1   Download

We report here the full coding sequence of a novel mouse putative membrane-associated mucin containing three extracellular EGF-like motifs and a mucin-like domain consisting of at least 20 tandem repeats of 124–126 amino acids. Screening a cosmid and a BAC libraries allowed to isolate several genomic clones. Genomic and cDNA sequence comparisons showed that the gene consists of 25 exons and 24 introns covering a genomic region of  52 kb. The first intron is  16 kb in length and is followed by an unusually large exon ( 9.5 kb) encoding Ser/Thr-rich tandemly repeated sequences....

10p system191 01-06-2013 44 4   Download

The plant enzyme phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) shows homology to histidine ammonia-lyase (HAL) whose structure has been solved by X-ray crystallography. Based on amino-acid sequence alignment of the two enzymes, mutagenesis was performed on amino-acid residues that were identical or similar to the active site residues in HAL to gain insight into the importance of this residues in PAL for substrate binding or catalysis. We mutated the following amino-acid residues: S203, R354, Y110, Y351, N260, Q348, F400, Q488 and L138....

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Laboratory for Lipoprotein Chemistry and 4Flanders Interuniversity Institute for Biotechnology, Department of Medical Protein Research, Faculty of Medicine, Department of Biochemistry, Ghent University, Belgium; 2Laboratory of Biomolecular Dynamics, Katholieke Universiteit Leuven, Belgium; 3Ecole Normale Supe´rieure, Paris, France Penetratin is a 16-amino-acid peptide, derived from the homeodomain of antennapedia, a Drosophila transcription factor, which can be used as a vector for the intracellular delivery of peptides or oligonucleotides....

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Heterologous expression of the extracellular domains (ECDs) of the nicotinic acetylcholine receptor (AChR) subunits may give large amounts of proteins for studying the functional and spatial characteristics of their ligand-binding sites. The ECD of the a7 subunit of the homo-oligomeric a7 neuronal AChR appears to be a more suitable object than the ECDs of other heteromeric neuronal or muscle-type AChRs. The rat a7 ECDs (amino-acid residues  1–210) were recently expressed in Escherichia coli as fusion proteins with maltose-binding protein...

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In this study, we isolated a 25-kDa novel snake venom protein, designated ablomin, from the venom of the Japanese Mamushi snake (Agkistrodon blomhoffi). The amino-acid sequence of this protein was determined by peptide sequencing and cDNA cloning. The deduced sequence showed high similarity to helothermine from the Mexican beaded lizard (Heloderma horridum horridum), which blocks voltage-gated calcium and potassium channels, and ryanodine receptors. Ablomin blocked contraction of rat tail arterial smooth muscle elicited by high K+-induced depolarization in the 0.

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Institute for Organic Chemistry, University of Karlsruhe, Germany; 2Institute for Organic Chemistry, Budapest University of Technology and Economics, Hungary Elucidation of the 3D structure of histidine ammonia-lyase (HAL, EC 4.3.1.3) from Pseudomonas putida by X-ray crystallography revealed that the electrophilic prosthetic group at the active site is 3,5-dihydro-5-methylidene-4H-i´ midazol-4-one (MIO) [Schwede, T.F., Retey, J., Schulz, G.E. (1999) Biochemistry, 38, 5355 –5361].

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The p25rum1 is an inhibitor of Cdc2 kinase expressed in fission yeast and plays an important role in cell-cycle control. As its amino-acid sequence suggests that p25rum1 has putative phosphorylation sites for mitogen-activated protein kinase (MAPK), we investigated the ability of MAPK to phosphorylate p25rum1. Direct in vitro kinase assay using GST-fusion proteins of wild-type as well as various mutants of p25rum1 demonstrated that MAPK phosphorylates the N-terminal portion of p25rum1 and residues Thr13 and Ser19 are major phosphorylation sites for MAPK....

11p research12 01-06-2013 46 4   Download

Strictosidine glucosidase (SG) is an enzyme that catalyses the second step in the biosynthesis of various classes of monoterpenoid indole alkaloids. Based on the comparison of cDNA sequences of SG from Catharanthus roseus and raucaffricine glucosidase (RG) from Rauvolfia serpentina, primers for RT-PCR were designed and the cDNA encoding SG was cloned from R. serpentina cell suspension cultures. The active enzyme was expressed in Escherichia coli and purified to homogeneity. Analysis of its deduced amino-acid sequence assigned the SG from R. serpentina to family 1 of glycosyl hydrolases.

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AnN-acyl-D-amino acid amidohydrolase (N-D-AAase) was identified in cell extracts of a strain, Iso1, isolated from an environment containing N-acetyl-D-methionine. The bac-terium was classified as Variovorax paradoxusby phylo-genetic analysis. The gene was cloned and sequenced. The gene consisted of a 1467-bpORF encoding a polypeptide of 488 amino acids. TheV.

11p research12 29-04-2013 44 3   Download

Cyclin-dependent kinase-5 (Cdk5) is a serine/threonine kinase activated by its neuron-specific activator, p35, or its truncated form, p25. It has been proposed that the deregu-lation of Cdk5 activity by association with p25 in human brain tissue disrupts the neuronal cytoskeleton and may be involved in neurodegenerative diseases such as Alzheimer’s disease.

8p research12 23-04-2013 32 2   Download

A novel lectin was isolated from leaves of the Japanese cycad,Cycas revolutaThunb. (gymnosperm), and its char-acteristics including amino acid composition, molecular mass, carbohydrate binding specificity and partial amino acid sequences were examined. The inhibition analysis of hemagglutinating activity with various sugars showed that the lectin has a carbohydrate-binding specificity similar to those of mannose recognizing, jacalin-related lectins.

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The characterization of the gene encodingLeishmania donovaniphosphofructokinase (PFK) and the biochemical properties of the expressedenzyme are reported.L. donovani has a singlePFKgene copyperhaploidgenome that encodes a polypeptide with a deducedmolecular mass of 53 988 and a pI of 9.26. The predicted amino acid sequence contains a C-terminal tripeptide that conforms to an established signal for glycosome targeting.

12p research12 23-04-2013 62 3   Download

Relaxin is an insulin-like peptide consisting of two separate chains (A and B) joined by two inter- and one intrachain disulfide bonds. Binding to its receptor requires an Arg–X– X–X–Arg–X–X–Ile motif in the B-chain. A relatedmember of the insulin superfamily, INSL3, has a tertiary structure that is predicted to be similar to relaxin. It also possesses an Arg–X–X–X–Arg motif within its B-chain, although this is displaced by four amino acids towards the C-terminus from the corresponding position within relaxin....

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Limitedproteolysis of the pyruvate decarboxylase (E1,a2b2 ) component of the pyruvate dehydrogenase (PDH) multi-enzyme complexofBacillus stearothermophilushas indicated the importance for catalysis of a site (Tyr281-Arg282) in the E1asubunit (Chauhan, H.J., Domingo, G.J., Jung, H.-I. & Perham, R.N. (2000)Eur. J. Biochem.267, 7158–7169). This site appears to be conserved in the a-subunit of hetero-tetrameric E1s and multiple sequence alignments suggest that there are additional conserved amino-acid residues in this region, part of a common pattern with the consensus sequence -YR-H-D-YR-DE-.

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A complementary DNA encoding a new bovine tryptase isoform (here named BLT) was cloned and sequenced from lung tissue. Analysis of sequence indicates the pres-ence of a 26-amino acid prepro-sequence and a 245 amino acid catalytic domain. It contains six different residues when compared with the previously characterized tryptase from bovine liver capsule (BLCT), with the most signifi-cant difference residing at the primary specificity S1 pocket.

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In the case of oxidized plastocyanin fromSynechocystissp. PCC6803, an NMR approach based on classical two and three dimensional experiments for sequential assignment leaves unobserved 14 out of 98 amino acids. A protocol which simply makes use of tailored versions of 2D HSQC and 3D CBCA(CO)NH and CBCANH leads to the identi-fication of nine of the above 14 residues.

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TheSTAT5(signal transducer andactivator of transcription 5) genewas isolated and characterized froma round-spotted pufferfish genomic library. This gene is composed of 19 exons spanning 11 kb. The full-length cDNA ofTetraodon fluviatilis STAT5(TfSTAT5) contains 2461 bp and encodes a protein of 785 amino acid residues. From the amino acid sequence comparison,TfSTAT5 is most similar to mouse STAT5a and STAT5bwith an overall identity of 76% and 78%, respectively, and has

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Acetohydroxyacid synthase (AHAS, EC 4.1.3.18) catalyses the first step in branched-chain amino acid biosynthesis and is the target for sulfonylurea and imidazolinone herbicides, which act as potent and specific inhibitors. Mutants of the enzyme have been identified that are resistant to particular herbicides.However, the selectivityof thesemutants towards various sulfonylureas and imidazolinones has not been determined systematically.

10p fptmusic 16-04-2013 26 3   Download

Soybean 4-kDa peptide, a hormone-like peptide, is a ligand for the 43-kDaprotein in legumes that functions as aprotein kinase and controls cell proliferation and differentiation. As this peptide stimulates proteinkinase activity, the interaction between the 4-kDa peptide (leginsulin) and the 43-kDa protein is considered important for signal transduction. However, the mechanism of interaction between the 4-kDa peptide and the 43-kDa protein is not clearly understood.

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