Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.5.1.5 (
urease
)
7,257
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A rapid, simple and inexpensive procedure for the determination of
urease
activity by using a thermal conductivity gas chromatography method is presented. The procedure is based on the determination of CO2 released in the
urease
reaction, and showed low coefficient of variation (c.v. less than 1%) and high sensitivity (detection limit 10(-12) mol). This procedure is also suitable for determination of other
decarboxylating
enzyme activities.
...
PMID:Determination of urease activity by thermal conductivity gas chromatography. 377 25
We have studied the effect of a crowded (macromolecular) solution on reaction rates of the
decarboxylating
enzymes
urease
, pyruvate decarboxylase and glutamate decarboxylase. A variety of crowding agents were used including haemoglobin, lysozyme, various dextrans and polyethylene glycol. Enzyme reaction rates of all three enzymes show two different types of effect that separate the globular proteins from the polysaccharides/polymers. Increasing concentration of globular proteins caused a dramatic rise in enzyme activity up to 30% crowding concentration then the activity decreased, whereas the polymers caused a concentration dependent decrease in activity. The viscosities of the globular proteins were low compared to the polymers. The increased activity with proteins may be due to the decreased amount of free water, which leads to higher effective concentration of substrates, or to an increased oligomeric state by self-association. The lower activities of all enzymes with all agents at high concentrations may be explained by a decrease in rates of diffusion. An increase in protein crowding (decrease in cell water content) may contribute to pathological conditions including cataract and Alzheimer's disease.
...
PMID:The effect of the presence of globular proteins and elongated polymers on enzyme activity. 1672 Jan 13
