Proteins and enzymes

Master's thesis of Science "Investigation into the modulation of circadian clock proteins by dietary compounds and small molecules" is structured as follows: Chapter 1 Introduction; Chapter 2 Identification of novel bioactive compounds from Olea europaea by evaluation of chemical compounds in the OliveNetTM library: in silico bioactivity and molecular modelling, and in vitro validation of hERG activity; Chapter 3 Modulation of circadian core clock proteins by dietary compounds; Chapter 4 Molecular mechanisms of action of selected olive phenolics against epigenetic modifiers and the structur...

235p runthenight04 02-02-2023 5 3   Download

Utilizing the remaining raw materials - fresh shark cartilage in hydrolysate processing and protein powder containing chondroitin sulfate and natural substances from shark cartilage (C. dussumieri) with environmentally friendly enzyme protease technology Directed to use as functional foods to support the treatment of osteoarthritis.

33p guitaracoustic09 14-01-2022 24 2   Download

Synthesis and structural determination of some 4-aminoquinazoline derivatives containing prop-2-yn-1-yloxy substituents at C-6 position; research and synthesize and determine the hybrid compound structure containing Quinazoline frame; research on carcinogenic activity and inhibition of acetylcholinesterase enzyme of synthetic compounds; studying protein docking and predicting the pharmacokinetic properties of some compounds that inhibit the enzyme acetylcholinesterase.

26p capheviahe27 23-02-2021 41 4   Download

Quantifying the multiple processes which control and modulate the extent of oral bioavailability for drug candidates is critical to accurate projection of human pharmacokinetics (PK). Understanding how gut wall metabolism and hepatic elimination factor into first-pass clearance of drugs has improved enormously. Typically, the cytochrome P450s, uridine 5′- diphosphate-glucuronosyltransferases and sulfotransferases, are the main enzyme classes responsible for drug metabolism. Knowledge of the isoforms functionally expressed within organs of first-pass clearance, their anatomical topology (e.

16p caothientrangnguyen 09-05-2020 19 1   Download

Shikimate kinase was chosen as a convenient representative example of the subclass of a/b proteins with which to examine the mechanism of protein folding. In this paper we report on the refolding of the enzyme after denaturation in urea. As shown by the changes in secondary and tertiary structure monitored by far UV circular dichroism (CD) and fluorescence, respectively, the enzyme was fully unfolded in 4 M urea. From an analysis of the unfolding curve in terms of the two-state model, the stability of the folded state could be estimated as 17 kJÆmol)1.

9p system191 01-06-2013 46 5   Download

Trehalose metabolism is an essential component of the stress response in yeast cells. In this work we show that the products of the principal genes involved in trehalose metabolism in Schizosaccharomyces pombe, tps1+ (coding for trehalose6-P synthase, Tps1p), ntp1+ (encoding neutral trehalase, Ntp1p) and tpp1+ (that codes for trehalose-6-P phosphatase, Tpp1p), interact in vitro with each other and with themselves to form protein complexes. Disruption of the gene tps1+ blocks the activation of the neutral trehalase induced by heat shock but not by osmotic stress.

9p system191 01-06-2013 28 4   Download

Certain amino acids, like glutamine and leucine, induce an anabolic response in liver. They activate p70 ribosomal protein S6 kinase (p70S6K) and acetyl-CoA carboxylase (ACC) involved in protein and fatty acids synthesis, respectively. In contrast, the AMP-activated protein kinase (AMPK), which senses the energy state of the cell and becomes activated under metabolic stress, inactivates by phosphorylation key enzymes in biosynthetic pathways thereby conserving ATP.

9p system191 01-06-2013 50 5   Download

Liver metabolism is influenced by hormones and nutrients. Amino acids such as glutamine or leucine induce an anabolic response, which resembles that of insulin in muscle and adipose tissue. In this work, the signalling pathways and the effects of insulin were compared to those of glutamine and leucine in isolated hepatocytes from normal and streptozotocin-diabetic rats.

9p system191 01-06-2013 46 5   Download

This review describes studies of particular enzymatically catalyzed reactions to investigate the possibility that catalysis is mediated by protein dynamics. That is, evolution has crafted the protein backbone of the enzyme to direct vibrations in such a fashion to speed reaction. The review presents the theoretical approach we have used to investigate this problem, but it is designed for the nonspecialist.

10p system191 01-06-2013 37 4   Download

The plastid transcription kinase (PTK), a component of the major RNA polymerase complex from mustard chloroplasts, has been implicated in redox-mediated regulation of plastid gene expression. A cloning strategy to define the PTK gene(s) resulted in the isolation of a full-length cDNA for a protein with overall high homology with the a subunit of cytosolic casein kinase (CK2) that contained an N-terminal extension for a putative plastid transit peptide.

9p system191 01-06-2013 45 4   Download

Pyruvate decarboxylase (EC 4.1.1.1) was isolated and purified from the yeast Kluyveromyces lactis. The properties of this enzyme relating to the native oligomeric state, the subunit size, the nucleotide sequence of the coding gene(s), the catalytic activity, and protein fluorescence as well as circular dichroism are very similar to those of the well characterized pyruvate decarboxylase species from yeast.

8p system191 01-06-2013 41 3   Download

To examine functions of two small heat shock proteins of Escherichia coli, IbpA and IbpB, we constructed His–IbpA and His–IbpB, in which a polyhistidine tag was fused to the N-terminals. Both purified His–IbpA and His–IbpB formed multimers, which have molecular masses of about 2.0– 3.0 MDa and consist of about 100–150 subunits.

11p system191 01-06-2013 41 4   Download

VanXYC, a bifunctional enzyme from VanC-phenotype Enterococcus gallinarum BM4174 that catalyses D,D-peptidase and D,D-carboxypeptidase activities, was purified as the native protein, as a maltose-binding protein fusion and with an N-terminal tag containing six histidine residues. The kinetic parameters of His6–VanXYC were measured for a variety of precursors of peptidoglycan synthesis involved in resistance: for D-Ala-D-Ala, the Km was 3.6 mM and kcat, 2.5 s)1; for UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-DAla (UDP-MurNAc-pentapeptide[Ala]), Km was 18.8 mM and kcat 6.

7p system191 01-06-2013 40 4   Download

Departamento de Fisiologıa de la Nutricion, Instituto Nacional de Ciencias Medicas y Nutricion ‘Salvador Zubiran’, Mexico; ´ ´ ´ ´ ´ Departamento de Patologıa Experimental, Instituto Nacional de Ciencias Medicas y Nutricion ‘Salvador Zubiran’,Mexico; 3Department of Biochemistry, Wake Forest University Medical Center, Winston-Salem, North Carolina, USA Branched chain amino-acid aminotransferase (BCAT) activity is present in fetal liver but the developmental pattern of mitochondrial BCAT (BCATm) expression in rat liver has not been studied.

8p system191 01-06-2013 47 6   Download

We previously reported that GTS1 is involved in regulating ultradian oscillations of the glycolytic pathway induced by cyanide in cell suspensions as well as oscillations of energy metabolism in aerobic continuous cultures. Here, we screened a yeast cDNA library for proteins that bind to Gts1p using the yeast two-hybrid system and cloned multiple TDH cDNAs encoding the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH).

10p research12 01-06-2013 40 3   Download

Angiotensin converting enzyme (ACE) was already discovered in insects in 1994, but its physiological role is still enigmatic. We have addressed this problem by purifying four new ACE substrates from the ovaries of the grey fleshfly, Neobellieria bullata. Their primary structures were identified as NKLKPSQWISLSD (Neb-ODAIF-11)13), NKLKPSQWI (Neb-ODAIF-11)9), SLKPSNWLTPSE (Neb-ODAIF-2) and LEQIYHL. Database analysis showed significant homology with amino acid sequence stretches as present in the N-terminal part of several fly yolk proteins....

9p research12 01-06-2013 36 3   Download

A splicing factor SF2/ASF is a natural substrate for the kinase activity of human topoisomerase I. This study demonstrates that SF2/ASF inhibits DNA cleavage by human topoisomerase I induced by the anti-cancer agent camptothecin. The inhibition is independent of the phosphorylation status of SF2/ASF. We show that the inhibition did not result from binding of SF2/ASF to DNA that would hinder interactions between topoisomerase I and DNA. Neither it was a consequence of a loss of sensitivity of the enzyme to camptothecin.

7p research12 01-06-2013 39 5   Download

Transglutaminase (TGase) catalyses the post-translational modification of proteins by transamidation of available glutamine residues. While several TGase genes of fish and arthropods have been cloned and appear to have similar structures to those of mammals, no homologous gene has been found in lower eukaryotes. We have cloned the acellular slime mold Physarum polycephalum TGase cDNA using RT-PCR with degenerated primers, based on the partial amino acid sequence of the purified enzyme. The cDNA contained a 2565-bp ORF encoding a 855-residue polypeptide.

10p research12 01-06-2013 48 4   Download

Cloning and over-expression of human glucose 6-phosphate dehydrogenase (Glc6P dehydrogenase) has for the first time allowed a detailed kinetic study of a preparation that is genetically homogeneous and in which all the protein molecules are of identical age. The steady-state kinetics of the recombinant enzyme, studied by fluorimetric initial-rate measurements, gave converging linear Lineweaver–Burk plots as expected for a ternary-complex mechanism.

8p research12 01-06-2013 59 4   Download

We report the cloning and functional charaterization of the full-length cDNA and gene encoding a Toxoplasma gondii DNA repair enzyme designated TgDRE. The gene is composed of three exons separated by two introns of 780 and 630 bp, and encodes a protein with a predicted molecular mass of 49.6 kDa. The native TgDRE protein, with a molecular mass of 60 kDa, is only detected in the virulent tachyzoite stage of T. gondii. However, the transcript is present in both asexual parasite stages, virulent tachyzoite and avirulent encysted bradyzoite. ...

9p research12 01-06-2013 33 5   Download