Biomaterial Database

Structure-activity studies of sulfate transfer: the hydrolysis and aminolysis of 3'-phosphoadenosine 5'-phosphosulfate (PAPS). 1995

C T Bedford, and A J Kirby, and C J Logan, and J N Drummond

School of Biological & Health Sciences, University of Westminster, London, U.K.

The pH-rate profile for the hydrolysis of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) in aqueous solution has been measured. Comparison with other data suggests that hydrolysis occurs by almost complete unimolecular elimination of sulfur trioxide, with weak involvement of a molecule of water in the transition state. The catalytic power (kcat/kuncat) of the sulfotransferases is estimated to be in the order of 10(10)-10(12). Amines--exemplified by morpholine--react spontaneously with PAPS in water at 39 degrees C by attack at both sulfuryl and (5')phosphoryl groups in a ratio of 2:3. The mechanism of activation of the coenzyme, PAPS, by the sulfotransferases that catalyse N-sulfation must involve suppression of its native N-phosphorylating reactivity and specific enhancement of its N-sulfating reactivity. Studies of the aminolysis of the coenzyme in aprotic solvent-water mixtures suggest how this might be accomplished.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009025	Morpholines		Tetrahydro-1,4-Oxazines,Tetrahydro 1,4 Oxazines
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D010724	Phosphoadenosine Phosphosulfate	3'-Phosphoadenosine-5'-phosphosulfate. Key intermediate in the formation by living cells of sulfate esters of phenols, alcohols, steroids, sulfated polysaccharides, and simple esters, such as choline sulfate. It is formed from sulfate ion and ATP in a two-step process. This compound also is an important step in the process of sulfur fixation in plants and microorganisms.	Adenosine-3'-phosphate-5'-Phosphosulfate,Adenosine 3' phosphate 5' Phosphosulfate,Phosphosulfate, Phosphoadenosine
D010879	Piperazines	Compounds that are derived from PIPERAZINE.
D002851	Chromatography, High Pressure Liquid	Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.	Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D004121	Dimethyl Sulfoxide	A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.	DMSO,Dimethyl Sulphoxide,Dimethylsulfoxide,Dimethylsulphinyl,Dimethylsulphoxide,Dimexide,Rheumabene,Rimso,Rimso 100,Rimso-50,Sclerosol,Sulfinylbis(methane),Rimso 50,Rimso50,Sulfoxide, Dimethyl,Sulphoxide, Dimethyl
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000588	Amines	A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Amine