Transferase systems

Morcillo, Y., Janer, G., and O Hara, S.C.M. et al. (2004). Interaction of tributyl tin with cytochrome P450 and UDP glucuronyl transferase systems of fish in vitro smdies. Environmental Toxicology and Chemistry 23, 990-996. 

An active glutathione S-transferase system was detected in the onion enzyme system when it was assayed with [ C]PCNB and GSH (9.). An initial rate of 14 nmol product/mg protein/hr was observed and a yield of 18 was obtained in 17 hr. HPLC indicated that S-(PCP)GSH was the only major conjugated product of this reaction. This was consistent with the Iji vivo studies with onion that showed that S-(PCP)GSH was the dominant GSH conjugate formed. In contrast, an enzyme from pea produced S-(PCP)GSH, S-(TCNP)GSH, and what appeared to be two isomeric S,S -(TCP)diGSH conjugates (6 ). 

Table I. ACTIVITY OF VARIOUS SUBSTRATES FOR THE METHYL TRANSFERASE SYSTEM FROM ONION ROOT /...

Walsh, C.T. Kabak, H.R. Vinylglycolic acid. An inactivator of the phos-phoenolpyruvate-phosphate transferase system in Escherichia coli. J. Biol. Chem., 248, 5456-5462 (1973)... 

Heller and Villemez299,300 solubilized, but did not separate, the D-mannosyltransferase and D-glucosyltransferase activities from this particulate-enzyme system, and found that, when only GDP-D-mannose is provided as the substrate, a/ -(1— 4)-linked D-mannan is synthesized and, when only GDP-D-glucose is present, ap-(l— 4)-linked D-glucan is produced. They further noted, with this transferase system, that incorporation of D-glucose from GDP-D-glucose into polysaccharide is a shortlived reaction that can be greatly extended if GDP-D-mannose is also included in the reaction mixture. 

Hanson and Anderson170 resolved the phosphorylation system of Acetobacter aerogenes into four components enzyme I, HPr, and two components required for the activity of enzyme II. The components of enzyme II are a protein of high molecular weight and a smaller, inducible protein that increases the affinity of the system for D-fructose. The D-fructose-PEP-transferase system is similar to those involved with D-fructose phosphorylation in Arthrobacter pyridinolis, and with hexose phosphorylation in Staphylococcus aureus.171... 

There is evidence that the thiosulphate sulphur-transferase system may not necessarily be the primary simplistic detoxification mechanism for CN as outlined briefly above, principally because little SCN penetrates the inner mitochondrial membrane to access the transferase system. A more general view of the role of sulphur in the detoxification process is that the supply of sulphane sulphur is from a rapidly equilibrating pool of potential sulphane sulphur donors, and these... 

G.C. Chemnitius, R.D. Schtnid, L-Malate determination in wines and fruit juices by flow injection analysis adaptation of coupled dehydrogenase/transferase system, Anal. Lett. 22 (1989) 2897. 

Chatterjee, S., Bhattacharya, S., 1984. Detoxification of industrial pollutants by the glutathione-S-transferase system in the liver of Anabas testudineus (Bloch). Toxicol. Lett. 22, 187-198. 

Figure 4. Distribution of C-mannose-containing saccharides on paper chromatogram in a system containing GDP-)mannose, peptidophosphogalacto-mannan and components of mannosyl-transferase system. The reaction mixture ( 2) was incubated at 25°C for 1 hr and the reaction stopped by heating for 2 min at 100°C and the reaction mixture was extracted with CHClf methanol, 2 1 (v/v) and the organic and aqueous layers chromatographed (12). The chromatograms were removed from the tank, driedy and cut into...

Figure 8. Location of C-mannosyl residues derived from C-phosphogalacto-mannan following acetolysis (13). A reaction mixture containing 30 mg phospho-galactomannan, 125 fig of crude mannosyl-transferase, and other components of the mannosyl-transferase system (13) were incubated for 2 hr and the reaction stopped and phosphogalactomannan reisolated. Twenty mg of phosphogalactomannan was obtained. The polymer was subjected to acetolysis and the products were deacetyl-ated and fractionated on Bio-Gel P-2 as...

Solute transport across the cytoplasmic membrane of bacteria occurs by two major mechanisms (i) Secondary transport systems transport by these systems is driven by electrochemical gradients and will lead to the translocation of solute in unmodified form (ii) Group translocation solute is substrate for a specific enzyme system in the membrane the enzyme reaction results in a chemical modification of the solute and release of the products at the cytoplasmic side. The only well-established group translocation system is the phosphoenolpyruvate phospho-transferase system (PTS) (see below). 

McGarry, J.D. Brown, N.F. (1997) The mitochondrial carnitine palmitoyl-transferase system. From concept to molecular analysis. Eur. J. Biochem. 244 1-14. 

In the case of natural rubber from Hevea brasiliensis, which is almost entirely made of cis-isoprene units, it could be assumed that ci5-prenyltransferase is exclusively involved in phase 2. Unfortunately it is more complex. Authors agree on phase 1, which is traws -condensation catalyzed by a cytosolic soluble trans-prenyl transferase" Famesyl diphosphate synthase has been cloned from rubber latex.The most probable prenyldiphosphate used as a primer for phase 2 is famesyl-PP (15) or geranylgeranyl-PP (16)." " Phase 2 is catalyzed by a still not clearly identified rubber transferase system. Different proteins have been... 

The situation is different when simulating the dynamics of the uptake of the carbon and energy source. Here, there is a high risk of failure if the dynamic behavior is predicted with Monod kinetics verified at different snapshot steady states in continuous or fed batch cultures. Application of these kinetics is questionable, because the steady state data of substrate uptake at different dilution rates may be corrupted by induction of different transporter systems depending on the steady state substrate concentrations. In addition to the variability of the affinity of the various transporter systems as clearly demonstrated for the yeast Saccharomyces cerevisiae, we do expect pronounced differences between permeases and phospho-transferase systems because of the clear distinctions in the influence of intracellular metabolites upon the uptake dynamics. 

A third form of congenital jaundice differs from the preceding one in that the bilirubin that accumulates in the blood is the direct type. Again, the pathogenesis of that disease is not know, but it cannot result from interference with the transferase system since bilirubin... 

When the transferase systems (transphosphorylases, transglycosidases, transpeptidases, transmethylases, transacylases, etc.) which function inside the cell, cease to act and compete with the transfer to water, the hydrolases take over and cause a certain amount of hydrolysis of the cellular contents. 

There may be failure of the liver to conjugate bilirubin as in physiological neonatal jaundice. Another condition where this occurs is Crigler-Najjar syndrome where there is a deficiency of the glucuronyl transferase system. In these conditions, the bilirubin is mainly of the unconjugated variety. 

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