Enzyme activation alteration

After 96 h, gill tissue respiration was reduced and liver enzyme activity altered. Similar effects seen for silver nitrate and silver acetate 38... 

R. Schuster and H. G. Holzhiitter, Use of mathematical models for predicting the metabolic effect of large scale enzyme activity alterations. Application to enzyme deficiencies of red blood cells. Eur. J. Biochem. 229(2), 403 418 (1995). 

The rates and routes of metabolism can vary with age and the lower rates and reduced routes of metabolism usually seen in the yoimg and the old can make them more susceptible to drug action. Differences in hormonal levels, in particular, can lead to differences in metabolism between sexes. Dietary and environmental factors such as the presence of alcohol and cigarette smoke can affect metabolism, as can certain disease conditions, e.g., liver disorders, diabetes. Such conditions can lead to decreased enzyme activity, altered hepatic blood flow, and changes in plasma protein levels which, in turn, can affect circulating active drug levels. 

Female Charles Foster rats, dosed and controls S.c. injection daily, 0.05 mg/kg body weight Fertility rate or litter size No changes with exposure, but implantation enzyme activities altered Nampoothiri and Gupta (2008)... 

Specificity for a particular charged substrate can be engineered into an enzyme by replacement of residues within the enzyme-active site to achieve electrostatic complementarity between the enzyme and substrate (75). Protein engineering, when coupled with detailed stmctural information, is a powerful technique that can be used to alter the catalytic activity of an enzyme in a predictable fashion. 

M (reduced sperm count Sinha et al. 1995 changes in enzyme activity Technical indicating altered spermatogenesis)... 

The correlation between altered enzyme activities and a given disease, i.e., the diagnostic accuracy should be based on accepted symptoms and laboratory changes. Tissue diagnoses should be used whenever possible as a standard of reference (22). 

A large number of amino acid transporters have been detected by isolating mutations which selectively inactivate one permease without altering enzyme activities involving the corresponding amino acid. Competitive inhibition, kinetics and regulatory behaviour have also been used as criteria to distinguish one transport system from another (see section 4.2). 

J. L. Mawdsley and R. G. Burns, Inoculation of plants with a Flavobacterium species results in altered rhizosphere enzyme activity. Soil Biol. Biochem. 26 871 (1994). 

The reported (14) mechanisms of action of allelochemlcals Include effects on root ultrastructure and subsequent Inhibition of Ion absorption and water uptake, effects on hormone-induced growth, alteration of membrane permeability, changes In lipid and organic acid metabolism, inhibition of protein synthesis and alteration of enzyme activity, and effects on stomatal opening and on photosynthesis. Reduced leaf water potential Is one result of treatment with ferulic and p-coumaric acids (15). Colton and Einhellig (16) found that aqueous extracts of velvetleaf (Abutllon theophrastl Medic.) Increased diffusive resistance In soybean fGlycine max. (L.) Merr.] leaves, probably as a result of stomatal closure. In addition, there was evidence of water stress and reduced quantities of chlorophyll In Inhibited plants. 

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