Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-12-28
pubmed:abstractText
The peptide hormone uroguanylin stimulates chloride secretion via activation of intestinal guanylyl cyclase C (GC-C). It is characterized by two disulfide bonds in a 1-3/2-4 pattern that causes the existence of two topological stereoisomers of which only one induces intracellular cGMP elevation. To obtain an unambiguous structure-function relationship of the isomers, we determined the solution structure of the separated uroguanylin isoforms using NMR spectroscopy. Both isomers adopt well-defined structures that correspond to those of the isomers of the related peptide guanylin. Furthermore, the structure of the GC-C-activating uroguanylin isomer A closely resembles the structure of the agonistic Escherichia coli heat-stable enterotoxin. Compared with guanylin isomers, the conformational interconversion of uroguanylin isomers is retarded significantly. As judged from chromatography and NMR spectroscopy, both uroguanylin isoforms are stable at low temperatures, but are subject to a slow pH-dependent mutual isomerization at 37 degrees C with an equilibrium isomer ratio of approximately 1:1. The conformational exchange is most likely under the sterical control of the carboxy-terminal leucine. These results imply that GC-C is activated by ligands exhibiting the molecular framework corresponding to the structure of uroguanylin isomer A.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Toxins, http://linkedlifedata.com/resource/pubmed/chemical/Enterotoxins, http://linkedlifedata.com/resource/pubmed/chemical/Gastrointestinal Hormones, http://linkedlifedata.com/resource/pubmed/chemical/Guanylate Cyclase, http://linkedlifedata.com/resource/pubmed/chemical/Natriuretic Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Protein Isoforms, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Guanylate Cyclase-Coupled, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Peptide, http://linkedlifedata.com/resource/pubmed/chemical/enterotoxin receptor, http://linkedlifedata.com/resource/pubmed/chemical/guanylin, http://linkedlifedata.com/resource/pubmed/chemical/heat stable toxin (E coli), http://linkedlifedata.com/resource/pubmed/chemical/uroguanylin
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1397-002X
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
229-40
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:9774236-Amino Acid Sequence, pubmed-meshheading:9774236-Bacterial Toxins, pubmed-meshheading:9774236-Enterotoxins, pubmed-meshheading:9774236-Enzyme Activation, pubmed-meshheading:9774236-Epithelial Cells, pubmed-meshheading:9774236-Gastrointestinal Hormones, pubmed-meshheading:9774236-Guanylate Cyclase, pubmed-meshheading:9774236-Humans, pubmed-meshheading:9774236-Molecular Sequence Data, pubmed-meshheading:9774236-Natriuretic Peptides, pubmed-meshheading:9774236-Nuclear Magnetic Resonance, Biomolecular, pubmed-meshheading:9774236-Peptides, pubmed-meshheading:9774236-Protein Conformation, pubmed-meshheading:9774236-Protein Isoforms, pubmed-meshheading:9774236-Receptors, Guanylate Cyclase-Coupled, pubmed-meshheading:9774236-Receptors, Peptide, pubmed-meshheading:9774236-Stimulation, Chemical, pubmed-meshheading:9774236-Structure-Activity Relationship, pubmed-meshheading:9774236-Thermodynamics
pubmed:year
1998
pubmed:articleTitle
One peptide, two topologies: structure and interconversion dynamics of human uroguanylin isomers.
pubmed:affiliation
Niedersächsisches Institut für Peptid-Forschung, Hannover, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't