The role of hydrophobic

The objectives of the thesis: The aim of the studies is to gain fundamental understanding of the role of hydrophobic and polar sequence on folding mechanism of proteins and aggregation of peptides

33p xacxuoc4321 09-07-2019 42 4   Download

Penicillin acylase of Escherichia coli catalyses the hydrolysis and synthesis of b-lactam antibiotics. To study the role of hydrophobic residues in these reactions, we have mutated three active-site phenylalanines. Mutation of aF146, bF24 and bF57 to Tyr, Trp, Ala or Leu yielded mutants that were still capable of hydrolysing the chromogenic substrate 2-nitro-5-[(phenylacetyl)amino]-benzoic acid. Mutations on positions aF146 and bF24 influenced both the hydrolytic and acyl transfer activity.

8p research12 01-06-2013 31 3   Download

Signal sequences often containa-helix-destabilizing amino acids within the hydrophobic core. In the precursor of the Escherichia coliouter-membrane protein PhoE,the glycine residue at position)10 (Gly )10 ) is thought to be responsible for the break in the a-helix. Previously,we showed that substitution of Gly )10 bya-helix-promoting residues (Ala, Cys or Leu) reduced the proton-motive force dependency of the translocation of the precursor,but the actual role of the helix breaker remained obscure. ...

8p tumor12 22-04-2013 34 3   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

Surfactant-like membranes containing the 21-residue peptide KLLLL-KLLLLKLLLLKLLLLK (KL4 ), have been clinically tested as a therapeu-tic agent for respiratory distress syndrome in premature infants. The aims of this study were to investigate the interactions between the KL4 peptide and lipid bilayers, and the role of both the lipid composition and KL4 structure on the surface adsorption activity of KL4 -containing membranes.

13p inspiron33 26-03-2013 40 4   Download

Serum- and glucocorticoid-induced protein kinase-1 (SGK-1) plays a crit-ical role in regulation of the epithelial sodium channel, ENaC. SGK-1 also shares significant catalytic domain homology with protein kinase B (PKB⁄AKT-1) and is a downstream effector of antiapoptotic phosphoinos-itide 3-kinase signaling.

16p inspiron33 25-03-2013 34 3   Download

According to their fold, pyridoxal 5¢-phosphate-dependent enzymes are grouped into five superfamilies. Fold Type I easily comprises the largest and most investigated group. The enzymes of this group have very similar 3D structures.

10p vinaphone15 28-02-2013 31 1   Download

Although plant non-specific lipid transfer proteins (ns-LTPs) are character-ized by their ability to bind and transfer a broad range of hydrophobic ligands in vitro, their biological functions in vivo remain unclear. Recently, it has been proposed that ns-LTPs may play a key role in plant defense mechanisms, particularly during the induction of systemic acquired resis-tance,

12p vinaphone15 28-02-2013 38 3   Download

Pyridoxal 5¢-phosphate-dependent enzymes may be grouped into five struc-tural superfamilies of proteins, corresponding to as many fold types. The fold type I is by far the largest and most investigated group. An important feature of this fold, which is characterized by the presence of two domains, appears to be the existence of three clusters of evolutionarily conserved hydrophobic contacts.

12p vinaphone15 27-02-2013 38 3   Download

d-Crystallin is the major structural protein in avian and reptilian eye lenses, and confers special refractive properties. The protein is a homotetramer arranged as a dimer of dimers. In the present study, the roles of the side chains of Glu267, Lys315, and Glu327, which provide hydrogen bonds at the double dimer interface, were investigated. Hydrophobic side chain sub-stitution led to all mutant proteins having an unstable dimer interface.

11p vinaphone15 25-02-2013 34 2   Download

Protein oligomeric complexes have emerged as a major target of current research because of their key role in aggregation processes in living systems andin vitro. Hydrophobic and charged surfaces may favour the self-assembly process by recruiting proteins and modifying their interactions. We found that equine lysozyme assembles into multimeric complexes with oleic acid (ELOA) at the solid–liquid interface within an ion-exchange chromatography column preconditioned with oleic acid.

15p vinaphone15 25-02-2013 51 4   Download

GlutathioneS-transferases (GSTs) catalyze the conjugation of glutathione to hydrophobic compounds, contributing to the metabolism of toxic chemicals. In this study, we show that two naturally occurring tau GSTs (GSTUs) exhibit distinctive kinetic parameters towards 1-chloro-2,4-dini-trobenzene (CDNB), although they differ only in three amino acids (Arg89, Glu117 and Ile172 in GSTU1 are replaced by Pro89, Lys117 and Val172 in GSTU2).

8p mobifone23 18-01-2013 42 3   Download

Tài liệu tham khảo về hóa-sinh bằng tiếng anh

8p suadau_1 08-09-2011 37 1   Download