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:C0040822 (
tremor
)
18,428
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have previously shown that a cryoactivatable inactive form of renin, which we have tentatively termed prorenin, occurs in human plasma. Plasma prorenin is measured by subtracting the endogenous plasma renin activity (PRA) from the total renin activity measured after cryoactivation. Cryoactivation is accomplished by
shaking
plasma at -5 degrees C for 4 days. Circulating prorenin averaged 5.6 +/- 0.8 (SE) ng/ml per hour in a group of 30 normal subjects and 5.1 +/- 1.0 ng/ml per hour in 25 hypertensive subjects during random sodium intake. In these two groups, prorenin ranged from zero to 36 times the endogenous renin level, averaging 2.5-fold in normal subjects and 3.4-fold in hypertensive subjects. During sodium deprivation prorenin more than doubled in 12 hypertensive subjects from a mean of 2.8 to 6.3 ng/ml per hour. In 25 anephric subjects, circulating prorenin was slightly lower than in normal subjects, averaging 3.4 +/- 0.9 ng/ml per hour (P less than 0.05). In contrast to our findings in nephric subjects, the low level of PRA measured in anephric subjects ((0.26 +/- 0.04 ng/ml per hour) was almost always a constant fraction of the measured prorenin. This led to the demonstration that prorenin can be inadvertently activated by chilling blood during processing for renin measurement and this often accounts for the small amount of renin measured in plasmas from anephric subjects. The error in routine PRA measurements due to inadvertent activation averaged +48% in anephric subjects and +17% in those with kidneys. Evaluation of the effect of processing bloods at room temperature revealed that net
angiotensin I
accumulation is less than 2% of that generated during incubation and can be ignored. Accordingly, to avoid the inadvertent activation of prorenin which can at times lead to a sizable and variable overestimation of PRA we recommend collecting and processing blood samples at room temperature and then storage of plasma completely frozen until the time for analysis.
...
PMID:Plasma prorenin in normal, hypertensive, and anephric subjects and its effect on renin measurements. 87 Feb 30
Angiotensin I-converting enzyme (ACE, EC3.4.15.1) plays an important role in regulating blood pressure. The C-domain of ACE has been identified as the main catalytic site of
angiotensin I
cleavage in vivo. The ACE gene fragment of the C-domain was amplified by PCR and cloned into the pPIC9K secretory expression plasmid. The recombinant plasmid was transformed into Pichia pastoris strain GS115. Positive clones were selected and subject to electroporation. Antibiotic G418 was used for the screening of multicopy inserts. After optimization of the expression system, the protein yield reached 0.5 g/L by flask-
shaking
culture fermentation, and enzyme activity reached 7.178 U/mL in the fermentation supernatant. The purity of the target protein obtained was 97% after Ni+ affinity chromatography. Enzyme inhibitory activity assay using Captopril showed that it is promising to use ACE-C domain as new generation of target for screening ACE inhibitor antihypertensive drugs.
...
PMID:[Expression of human angiotensin converting enzyme-C domain in Pichia pastoris]. 2068 12