Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.2 (guanylate cyclase)
 8,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An extremely rapid and sensitive assay for guanylate cyclase utilizing [alpha-32P]-GTP has been developed. It involves incubation of 5-100 mug of enzyme protein with 1 mM [alpha-32P]-GTP in 40 mM Tris HC1 buffer (pH 7.4) containing 3-3 mM MnSO2, 10 mM theophylline and 1 mM cyclic GMP. The reaction is terminated by addition of EDTA, and [32P]-cyclic GMP formed is isolated by sequential chromatography on Dowex-50-H+ and alumina. Recovery of 75-85% of [3H]-cyclic GMP and a blank of 0.001-0.003% of added [32P]-GTP was routinely obtained. The [32P] radioactivity isolated was shown to be cyclic GMP by a variety of techniques. The assay has also been shown to be applicable for a variety of tissues.
 ...
PMID:A rapid method for the assay of guanylate cyclase. 0 69

Various analytical approaches have been used to measure endothelium-derived nitric oxide (NO). We have detected NO in perfusates with a sample size as low as 2 ml after acidification with 4 N HC1 to pH less than 2 at 25 degrees C by using a Nitric Oxide Analyser (Sievers, Colorado). This procedure had the advantage that the detectable level of NO was enhanced by the self-decomposition of HNO2 when the PH less than pKa of NHO2 (pKa = 3.15) and also the reaction temperature of 25 degrees C substantially increased the half-line of NO. Palmer, et al., measured NO released by cultured porcine endothelial cells by chemiluminescence after passing cell effluents continuously at a rate of 5 ml/min into 75 ml of 1% sodium iodide in glacial acetic acid. The larger volumes involved in this method for continuous refluxing, made it less desirable for the detection of endothelium-derived nitric oxide. Feelisch et al. utilized the activation of soluble guanylate cyclase, as well as, the quantitative oxidation of oxyhemoglobin to methemoglobin in aqueous solutions by NO as a means of measuring nitric oxide. We describe here a modification of our earlier micromethod which now enables us to detect NO after complete reduction with glacial acetic acid and sodium iodide. A comparison of the two procedures indicate that while freshly prepared NO standard solutions gave identical chemiluminescence response with and without reduction, effluents from bovine intrapulmonary artery under basal conditions gave substantially higher values upon reduction.
 ...
PMID:Reduction of biological effluents in purge and trap micro reaction vessels and detection of endothelium-derived nitric oxide (edno) by chemiluminescence. 194 75