Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.5.5 (CPS)
 1,262 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The reversed-phase high-performance liquid chromatography of three synthetic opioid peptides, 5leucine-enkephalin, 5methionine-enkephalin and [D-2alanine]-5methionine enkephalin, has been studied after their pre-column fluorogenic derivatization with naphthalene-2,3-dicarboxaldehyde in the presence of cyanide to the corresponding 1-cyanobenz[f]isoindole (CBI) derivatives. The chromatographic properties of the three synthetic CBI-peptides were characterized using three different stationary phases, ODS Hypersil, CPS Hypersil and Spherisorb Phenyl, eluted with mobile phases containing various concentrations of methanol, tetrahydrofuran or acetonitrile in 26 mM trifluoroacetic acid, adjusted to pH 3.5. The data obtained using single chromatographic columns were used to design a multi-dimensional system in which the three synthetic CBI-peptides of interest were transferred as a single fraction from one column to a second. The first column served to separate the peptides from the majority of the material in the samples, and the second column was used to separate the three CBI-peptides from each other. The best separation was achieved in which the first column was Spherisorb Phenyl and the second column was ODS Hypersil. Both columns were eluted with a mobile phase of 45% acetonitrile (v/v) in 26 mM trifluoroacetic acid (pH 3.5) at a flow-rate of 1.0 ml/min. The method has been applied to the determination of leucine- and methionine-enkephalin-like fluorescence in the striatum of the rat brain.
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PMID:Multi-dimensional high-performance liquid chromatography of opioid peptides following pre-column derivatization with naphthalene-2,3-dicarboxaldehyde in the presence of cyanide ion. Preliminary results on the determination of leucine- and methionine-enkephalin-like fluorescence in the striatum region of the rat brain. 259 17

The activity and stability of carbamoyl-phosphate synthetase (EC 6.3.4.16) may involve hydrophobic and ionic bonds within the enzyme. The 1-anilino-8-naphthalene sulfonate (ANS) equilibrium binding method with hydrophobic and ionic sites in enzymes, therefore, seemed suitable for the study of the acetylglutamate activation and ATP binding of the enzyme. The enzyme had a high affinity for the dye but low fluorescent yields. The enzyme had 32-88 ANS binding sites, depending on combination with ATP and acetylglutamate, and individual affinity constants for each combination. Despite the large number of binding sites, the acetylglutamate and ATP concentrations for half-maximal fluorescent change (10-40 microM) corresponded to the high-affinity bound ATP (ATPB) and acetylglutamate Kd values. In kinetic studies, ANS competed with ATP or acetylglutamate. The extrapolated ANS Ki values for ATP or acetylglutamate were both 35 microM. This value agreed with the ANS Kd value of the enzyme X ATP conformation, indicating that this was the conformation competed for by ANS. Since ANS did not influence the HCO3-dependent ATPase, ANS was concluded to compete with the ATPB binding conformation and transitional changes. This study suggests that part of the activator role of acetylglutamate may be to change the tertiary structure of the enzyme to induce hydrophobic sites which are accessible to ANS and possibly at the ATPB site.
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PMID:Fluorescent probe study with 1-anilino-8-naphthalene sulfonate on acetylglutamate activation, ATP binding and conformational changes of the rat liver carbamoyl-phosphate synthetase. 687 Dec 32