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)

The paper gives data on the role of heme in the functioning soluble forms of guanylate cyclase (of human platelets, rat heart and platelets), on the mechanism of nitrogen oxide-induced heme-dependent activation of enzymes, on the role of platelet guanylate cyclase in the regulation of human platelet aggregation/disaggregation and on the mechanism of antihypertensive and antiaggregatory action of enzyme activators. The instability of relationships of the protein molecule of human platelet guanylate cyclase and heme (regarded as a prosthetic group of the enzyme) results in heme loss during purification of the enzyme and preparation of a heme-deficient agent having a drastically reduced ability to sodium nitroprusside activation. Soluble rat platelet guanylate cyclase was found to be present in these cell originally in a heme-deficient form, it was not activated by sodium nitroprusside and, unlike the routine concepts, heme is not a moiety of this enzyme molecule. The water soluble antioxidant carnosine (beta-alanyl-L-histidine) inhibits sodium nitroprusside activation of guanylate cyclase by interacting with the heme of enzyme of the NO group of nitroprusside and may be useful to reveal the degree of htmt saturation of guanylate cyclase. The study of the mechanism of activation of guanylate cyclase by nitroso complexes of transition metals (Fe, Cr, Co) showed that their realization of antihypertensive effects required only heme-dependent activation of the enzyme. ADF-induced aggregation of human (donor) platelets is followed by stimulation of guanylate cyclase by various activators (despite heme involvement in the mechanism of activation) with concurrent elevations of platelet cGMP levels.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Soluble forms of guanylate cyclases: mechanism of activation by nitrogen oxide and role in platelet aggregation]. 775 30

The nematode Caenorhabditis elegans has complex, naturally variable behavioral responses to environmental oxygen, food, and other animals. C. elegans detects oxygen through soluble guanylate cyclase homologs (sGCs) and responds to it differently depending on the activity of the neuropeptide receptor NPR-1: npr-1(lf) and naturally isolated npr-1(215F) animals avoid high oxygen and aggregate in the presence of food; npr-1(215V) animals do not. We show here that hyperoxia avoidance integrates food with npr-1 activity through neuromodulation of a distributed oxygen-sensing network. Hyperoxia avoidance is stimulated by sGC-expressing oxygen-sensing neurons, nociceptive neurons, and ADF sensory neurons. In npr-1(215V) animals, the switch from weak aerotaxis on food to strong aerotaxis in its absence requires close regulation of the neurotransmitter serotonin in the ADF neurons; high levels of ADF serotonin promote hyperoxia avoidance. In npr-1(lf) animals, food regulation is masked by increased activity of the oxygen-sensing neurons. Hyperoxia avoidance is also regulated by the neuronal TGF-beta homolog DAF-7, a secreted mediator of crowding and stress responses. DAF-7 inhibits serotonin synthesis in ADF, suggesting that ADF serotonin is a convergence point for regulation of hyperoxia avoidance. Coalitions of neurons that promote and repress hyperoxia avoidance generate a subtle and flexible response to environmental oxygen.
 ...
PMID:A distributed chemosensory circuit for oxygen preference in C. elegans. 2007 37