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: UMLS:C0085631 (
agitation
)
12,064
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A simple and rapid procedure to make yeast cells permeable by agitating with toluene-ethanol, (TE) 1:4, v/v was developed. The permeated cells retained their ability to catalyze certain enzyme reactions. Temperature and duration of
agitation
during TE treatment played an important role in retention of the catalytic potential of permeated cells. The in situ assay using permeated cell preparations was more sensitive even in the absence of added cofactors than in the vitro assay in detecting assimilatory nitrate reductase (NAD(P)H:nitrate oxidoreductase, EC 1.6.6.2) (
NAR
) activity in Candida utilis. Using in situ assay technique, different mechanisms regulating the biosynthesis of
NAR
in C. utilis were investigated. Nitrogen starvation did not lead to derepression of
NAR
. NO3-ions were absolutely essential for induction and maintenance of high levels of
NAR
activity. Cells grown on ammonium nitrate possessed relatively lower levels of
NAR
. Kinetics of
NAR
induction were followed as a function of time and inducer concentration. The influence of various cations on the induction of
NAR
by nitrate was investigated. A wide range of D-amino acids induced
NAR
synthesis. Of 22 L-amino acids tested only phenylalanine induced significant levels of
NAR
. Various intermediates of the pathway of nitrate reduction influenced the rate of
NAR
induction. There was a rapid disappearance of in vivo activity of the enzyme of induced yeast cells on nitrogen starvation, and the rate of loss was accelerated by the presence of NH4+.
...
PMID:Regulatory properties of yeast nitrate reductase in situ. 94 16
