|别名||1-乙酰咪唑 ;N-乙酰基咪唑，1-乙酰基咪唑;NAI 1-acetyl-imidazol 1-acetyl-1h-imidazol n-acetylimidazole|
|个人防护设备||Eyeshields,Gloves,type N95 (US),type P1 (EN143) respirator filter|
Identification of ionizable groups essential for the enzyme catalysis on glutathione S-transferase P.
The pH-Vmax/KmGSH plot of glutathione S-transferase P (GST-P) showed a bell-shaped profile, indicating bifunctional catalysis for glutathione (GSH) conjugation. The ionization constant (Ke) and the he...Read More
Acetylation of prostaglandin endoperoxide synthase by N-acetylimidazole: comparison to acetylation by aspirin.
Treatment of prostaglandin endoperoxide (PGH) synthase apoprotein with a 100- or 1000-fold excess of N-acetylimidazole (NAI) led to time-dependent inactivation of both cyclooxygenase and peroxide acti...Read More
Structural and functional differentiation of three groups of tyrosine residues by acetylation of N-acetylimidazole in manganese stabilizing protein.
To study its contribution to the assembly of the green plant manganese stabilizing protein (MSP) into photosystem II (PSII), tyrosine residues were specifically acetylated using N-acetylimidazole (NAI...Read More
Stability, structural and suicide inactivation changes of Mushroom tyrosinase after acetylation by N-acetylimidazole
Modification (acetylation) of Tyr residues with N-acetylimidazole protects outstandingly mushroom tyrosinase (MT) from the suicide inactivation in the presence of its catecholic substrate, 4-[(4-methy...Read More
Cinnamomin is a type II ribosome-inactivating protein (RIP) and its A-chain (CTA) is a RNA N-glycosidase. It is observed that modification of tyrosine residues by N-acetylimidazole (N-AI) causes almos...Read More
Involvement of conserved histidine, lysine and tyrosine residues in the mechanism of DNA cleavage by the caspase-3 activated DNase CAD.
The caspase-activated DNase (CAD) is involved in DNA degradation during apoptosis. Chemical modification of murine CAD with the lysine-specific reagent 2,4,6-trinitrobenzenesulphonic acid and the tyro...Read More
Insights into the reaction mechanism of the diisopropyl fluorophosphatase from Loligo vulgaris by means of kinetic studies, chemical modification and site-directed mutagenesis.
Kinetic measurements, chemical modification and site-directed mutagenesis have been employed to gain deeper insights into the reaction mechanism of the diisopropyl fluorophosphatase (DFPase) from Loli...Read More
Chemical modification of xylanase from Trichosporon cutaneum shows the presence of carboxyl groups and cysteine residues essential for enzyme activity.
The endo-beta-1,4-xylanase (EC 184.108.40.206) from Trichosporon cutaneum was chemically modified using amino acid-specific reagents. The enzyme does not bear arginines essential for activity, since 1,2-cycl...Read More
Acetylation of alpha-crystallin with N-acetylimidazole and its influence upon the native aggregate and subunit reassembly.
An attempt has been made to investigate the involvement and importance of some of the hydrogen bond forming amino acid side chains in intra and inter subunit interactions in alpha-crystallin assembly....Read More
HlyC, the internal protein acyltransferase that activates hemolysin toxin: the role of conserved tyrosine and arginine residues in enzymatic activity as probed by chemical modification and site-directed mutagenesis.
Internal fatty acylation of proteins is a recognized means of modifying biological behavior. Escherichia coli hemolysin A (HlyA), a toxic protein, is transcribed as a nontoxic protein and made toxic b...Read More
Aminopeptidase A (EC 220.127.116.11; APA) is a 130 kDa membrane-bound zinc enzyme that contains the consensus sequence HEXXH (residues 385-389) conserved among the zinc metalloprotease family. In this motif...Read More
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Changes in the level and activation state of the plasma membrane H(+)-ATPase during aging of red beet slices.
The effect of aging on the plasma membrane (PM) H(+)-ATPase of red beet (Beta vulgaris L.) parenchyma discs was analyzed in PM purified by aqueous two-phase partitioning. Aging increased both the acti...Read More
Specificity of Aspartokinase III fromEscherichia coliand an Examination of Important Catalytic Residues
Aspartokinase III (AK III) has been purified from a plasmid-containing strain ofEscherichia coli.The enzyme shows broad specificity for the phosphoryl acceptor substrate. Structural analogs of asparti...Read More
Based on strict conservation of a tyrosine residue in 24 polygalacturonases, tyrosine modification was assessed in two different forms of the Aspergillus enzyme. The second subform was unknown in stru...Read More
Specific derivatization of the active site tyrosine in dUTPase perturbs ligand binding to the active site.
Selective modification of one (of three) tyrosine residue per enzyme monomer leads to inactivation of dUTPase of the retrovirus equine infectious anemia virus (EIAV). The substrate dUMP and the cofact...Read More
Ames tests have been performed with imidazole and its principal metabolites, hydantoin and hydantoic acid. N-Acetyl-imidazole, a potential metabolite resulting from the action of intestinal bacteria, ...Read More
Elimination of polarity in the carotenoid terminus promotes the exposure of B850-binding sites (Tyr 44, 45) and ANS-mediated energy transfer in LH2 complexes of Rhodobacter sphaeroides.
Carotenoids in the peripheral light-harvesting complexes (LH2) of the green mutant (GM309) of Rhodobacter sphaeroides were identified as containing neurosporenes, which lack the polar CH(3)O group, co...Read More
Peroxynitrite (ONOO-) toxicity is associated with protein oxidation and/or tyrosine nitration, usually resulting in inhibition of enzyme activity. We examined the effect of ONOO- on the activity of pu...Read More
Regulation of the Reduced-Folate Transporter by Nitric Oxide in Cultured Human Retinal Pigment Epithelial Cells
The regulation of the reduced-folate transporter (RFT) by nitric oxide (NO) was analyzed in human retinal pigment epithelial (HRPE) cells. NO inhibited specifically and reversibly the uptake ofN^5-met...Read More
Reaction of ovine prolactin (oPRL) with a 150-fold molar excess of N-acetylimidazole over protein content resulted in the modification of 2.5 tyrosine residues and 1.2 lysine residues. Acetylation gre...Read More
dUTP nucleotidohydrolase (dUTPase, EC 18.104.22.168) from E. coli contains a total of six tyrosine residues per trimer. About half of them were found to be susceptible to acetylation with N-acetylimidazole...Read More
Chemical modification of leukotriene A4 hydrolase. Indications for essential tyrosyl and arginyl residues at the active site.
We have employed chemical modification to identify amino acids essential for the catalytic activities of the bifunctional zinc metalloenzyme leukotriene A4 hydrolase (EC 22.214.171.124). The epoxide hydrolas...Read More
Chemical reagents of polypeptides side chain: relationships between solubility properties and ability to cross the inner mitochondrial membrane.
The correlation between the solubility properties of DCCD and EDAC (carboxyl specific groups reagents) and AI, NBD-Cl and TNM (tyrosyl specific reagents) and their efficiency to penetrate through the ...Read More
Chemical modification of active site residues in gamma-glutamyl transpeptidase. Aspartate 422 and cysteine 453.
gamma-Glutamyl transpeptidase, an enzyme of central significance in glutathione metabolism, is inactivated by iodoacetamide, which esterifies an active site carboxyl group identified here as that of A...Read More