Side chain

This property is provided by maintaining synchronized states on each side. In our article, we will analyze the risk of desynchronizing states between parties in the Signal protocol if at least one of those parties in this protocol uses a weak random source.

8p viyoko 01-10-2024 2 1   Download

Safrol is a natural product, and presents especially in Sassafras oil with 80% abundance. Sassafras oil has been used for long time for treatment of some diseases such as influenza, trouble digestion, stomach and arthritis [1]. Otherwise, Sassafras oil was also used in food and cosmetic industries. Some derivatives of safrol such as heliotropin is a precious perfume used widely in cosmetic industry. Heliotropin was prepared by oxidation of isosafrol [2, 3].

3p uocvong04 24-09-2015 37 2   Download

FTIR spectroscopy has been applied to study the coordination structures of Mg2þ and Ca2þ ions bound in Akazara scallop troponin C (TnC), which contains only a single Ca2þ binding site. The region of the COO – antisymmetric stretch provides information about the coordination modes of COO – groups to the metal ions: bidentate, unidentate, or pseudo-bridging. Two bands were observed at 1584 and 1567 cm21 in the apo state, whereas additional bands were observed at 1543 and 1601 cm21 in the Ca2þ-bound and Mg2þ-bound states, respectively.

7p system191 01-06-2013 38 2   Download

Introducing site-directed mutations in surface-exposed residues of subunit II of the heme aa3 cytochrome c oxidase of Paracoccus denitrificans, we analyze the kinetic parameters of electron transfer from reduced horse heart cytochrome c. Specifically we address the following issues: (a) which residues on oxidase contribute to the docking site for cytochrome c, (b) is an aromatic side chain required for electron entry from cytochrome c, and (c) what is the molecular basis for the previously observed biphasic reaction kinetics....

9p system191 01-06-2013 36 3   Download

Departamento de Bioquı´mica y Biologı´a Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, Spain; Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA Reduction potential determinations of K75E, E139K and E301A ferredoxin-NADP+ reductases provide valuable information concerning the factors that contribute to tune the flavin reduction potential. Thus, while E139 is not involved in such modulation, the K75 side-chain tunes the flavin potential by creating a defined environment that modulates the FAD conformation. ...

6p system191 01-06-2013 33 4   Download

Cys341 of carboxypeptidase Y, which constitutes one side of the solvent-accessible surface of the S1 binding pocket, was replaced with Gly, Ser, Asp, Val, Phe or His by site-directed mutagenesis. Kinetic analysis, using Cbz-dipeptide substrates, revealed that polar amino acids at the 341 position increased Km whereas hydrophobic amino acids in this position tended to decrease Km.

6p system191 01-06-2013 40 4   Download

Protein phosphorylation is a key mechanism for intracellular signal transduction in both prokaryotic and eukaryotic cells. Vertebrate proteins are prevalently phosphorylated on side chains that contain a hydroxyl group, such as serine, threonine and tyrosine residues. In the past decade, however, an increasing number of examples of histidine phosphorylation has been described.

5p research12 01-06-2013 52 3   Download

Calcitonin (Ct) is a 32-residue peptide hormone that is mainly known for its hypocalcemic effect and the inhibition of bone resorption. Our previous studies have led to potent, side-chain lactam-bridged human Ct (hCt) analogues [Kapurniotu, A. Kayed, R., Taylor, J.W. & Voelter W. (1999) Eur. J. Biochem.265, 606±618; Kapurniotu, A. & Taylor, J.W. (1995)J. Med. Chem.38, 836±847]. We have hypothesized that a possibly type Ibturn/bsheet confor-mation in the region 17±21 may play an important role in hCt bioactivity. ...

12p research12 01-06-2013 46 5   Download

An arti®cial peroxidase-like hemoprotein has been obtained by associating a monoclonal antibody, 13G10, and its iron(III)±a,a,a,b-meso-tetrakis(ortho-carboxyphenyl)por-phyrin [Fe(ToCPP)] hapten. In this antibody, about two-thirds of the porphyrinmoiety is inserted in the binding site, its ortho-COOH substituents being recognized by amino-acids of the protein, and a carboxylic acid side chain of the protein acts as a general acid base catalyst in the heterolytic cleavage of the O±O bond of H2O2, but no amino-acid res-idue is actingas anaxial ligandof the iron....

11p research12 23-04-2013 35 2   Download

Human cytochrome P450 17a-hydroxylase (CYP17) cata-lyses not only the 17a-hydroxlation of pregnenolone and progesterone and the C17,20-side chain cleavage (lyase) of 17a-hydroxypregnenolone, necessary for the biosynthesis of C21-glucocorticoids and C19-androgens, but also catalyses the 16a-hydroxylation of progesterone. In efforts to under-stand the complex enzymology of CYP17, structure/func-tion relationships have been reported previously after expressingrecombinant DNAs, encodingCYP17 from various species, in nonsteroidogenic mammalian or yeast cells. ...

9p tumor12 22-04-2013 42 2   Download

The role of the negative charge of the E139 side-chain of AnabaenaFerredoxin-NADP + reductase (FNR) in steering appropriate docking with its substrates ferredoxin, flavo-doxin and NADP + /H, that leads to efficient electron transfer (ET) is analysed by characterization of several E139 FNRmutants. Replacement of E139 affects the interaction with the different FNRsubstrates in very different ways.

10p tumor12 22-04-2013 37 2   Download

The structure–activity relations of a series of synthetic phenoxazone drugs with aminoalkyl side chains of variable length and different terminal groups were investigated by examining their biological activity and DNA complexation affinity. Biological activitywas determined fromtheir ability to induce apoptosis and cell cycle perturbations (activation of cell cycle checkpoints) using the human malignant MOLT-3 cell line. The thermodynamic parameters of drug– DNA complexation were determined by differential scan-ning calorimetry....

8p tumor12 20-04-2013 37 4   Download

The analysis of the structure and function of long chain-producing polyprenyl diphosphate synthase, which syn-thesizes the side chain of ubiquinone, has largely focused on the prokaryotic enzymes, and little is known about the eukaryotic counterparts. Here we show that decaprenyl diphosphate synthase fromSchizosaccharomyces pombeis comprised of a novel protein named Dlp1 acting in part-nership with Dps1. Dps1 is highly homologous to other prenyl diphosphate synthases but Dlp1 shares only weak homologywithDps1....

9p tumor12 20-04-2013 33 2   Download

As one of the most important families of non-natural poly-mers with the propensity to form well-defined secondary structures, theb-peptides are attracting increasing attention. The compounds incorporatingb-amino acid residues have found various applications in medicinal chemistry and biochemistry.The conformational pool ofb-peptides com-prises several periodic folded conformations, which can be classified as helices, and nonpolar and polar strands.The latter two are prone to form pleated sheets.

10p tumor12 20-04-2013 30 4   Download

One-electron oxidation of six different c-type lysozymes from hen egg white, turkey egg white, human milk, horse milk, camel stomach and tortoise was studied by gamma-and pulse-radiolysis.In the first step, one tryptophan side chain is oxidized to indolyl free radical, which is produced quantitatively.As shown already, the indolyl radical subse-quently oxidizes a tyrosine side chain to the phenoxy radical in an intramolecular reaction.However this reaction is not total and its stoichiometry depends on the protein.Rate constants also vary between proteins, from 120Æs )1 to 1000Æs )1 at pH 7.

7p tumor12 20-04-2013 40 2   Download

Engineered yeast cells efficiently convert ergosta-5-eneol to pregnenolone and progesterone provided that endogenous pregnenolone acetylase activity is disrupted and that heterologous sterolD7-reductase, cytochrome P450 side chain cleavage (CYP11A1) and 3b hydroxysteroid dehydrogenase/isomerase (3b-HSD) activities are present. CYP11A1activity requires the expressionof themammalian NADPH-adrenodoxin reductase (Adrp) and adrenodoxin (Adxp) proteins as electron carriers.

13p tumor12 20-04-2013 27 2   Download

Strains ofPseudomonas syringaepv. porri are characterized by a number of pathovar-specific phenotypic and genomic characters and constitute a highly homogeneous group. Using monoclonal antibodies, they all were classified in a novelP. syringaeserogroup O9. The O polysaccharides (OPS) isolated from the lipopolysaccharides (LPS) of P. syringaepv.

8p tumor12 20-04-2013 38 3   Download

The antigenicity ofCandida lusitaniaecells was found to be thesameasthatof Candida albicansserotype A cells, i.e. both cell wall mannans react with factors 1, 4, 5, and 6 sera of Candida Check. However, the structure of the mannan of C. lusitaniaewas significantly different from that of C. albicansserotype A, and we found novelb-1,2 linkages among the side-chainoligosaccharides,Manb1fi2Manb1fi 2Mana1fi2Mana1fi2Man (LM5), and Manb1fi2Man-b1fi2Manb1fi2Mana1fi2Mana1fi2Man (LM6).

11p fptmusic 16-04-2013 55 6   Download

A structural motif called the small exterior hydrophobic cluster (SEHC) has been proposed to explain the stabilizing effect mediated by solvent-exposed hydrophobic residues; however, little is known about its biological roles. Unusually, in D 5 -3-ketosteroid isomerase from Pseudomonas putida biotype B (KSI-PI) Trp92 is exposed to solvent on the protein surface, forming a SEHC with the side-chains of Leu125 and Val127.

13p awards 06-04-2013 36 3   Download

hort hydrogen bonds are present in many chemical and biological sys-tems. It is well known that these short hydrogen bonds are found in the active site of enzymes and aid enzyme catalysis. This study aims to system-atically characterize all short hydrogen bonds from a nonredundant dataset of protein structures. The study has revealed that short hydrogen bonds are commonly found in proteins and are widely present in different regions of the protein chain, such as the backbone or side chain, and in different secondary structural regions such as helices, strands and turns. ...

14p awards 06-04-2013 43 3   Download