File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Effects of iodination of tyrosyl residues on the binding and action of glucagon at its receptor

TitleEffects of iodination of tyrosyl residues on the binding and action of glucagon at its receptor
Authors
Issue Date1976
PublisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/biochemistry
Citation
Biochemistry, 1976, v. 15 n. 20, p. 4537-4540 How to Cite?
AbstractThe binding and action of glucagon at its receptor in hepatic plasma membranes have been compared, as a function of pH, with that of glucagon containing iodotyrosyl residues. Iodinated glucagon, at pH 7.0 and below, binds to the receptor and activates adenylate cyclase with an affinity about threefold higher than that of native glucagon. At pH 8.5, the affinity of the receptor for native glucagon is the same as that seen at pH 7.0. However, iodinated glucagon binds with a lowered affinity with increasing pH. The decreased affinity of the iodinated hormone correlates with ionization of the iodotyrosyl phenoxy group, which has a pK a of 8.2. It is suggested that the decreased affinity is actually due to the inability of the ionized iodoglucagon to bind to the receptor. The relative potency of native and iodoglucagon will depend, therefore, on the concentrations of ionized and un-ionized species of iodoglucagon, which in turn depend on the pH of the medium. We conclude that incorporation of iodine atoms in the tyrosyl residues of glucagon has two major effects: (i) the iodine atom increases hydrophobic interaction of the hormone with the receptor and (ii) ionization of the phenoxy groups results in the loss of biological activity possibly as the result of loss of hydrogen bonding capability. Thus, the tyrosyl residues in glucagon are critically involved in the function of the hormone.
Persistent Identifierhttp://hdl.handle.net/10722/167437
ISSN
2015 Impact Factor: 2.876
2015 SCImago Journal Rankings: 1.769
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorLin, MCen_US
dc.contributor.authorNicosia, Sen_US
dc.contributor.authorRodbell, Men_US
dc.date.accessioned2012-10-08T03:06:58Z-
dc.date.available2012-10-08T03:06:58Z-
dc.date.issued1976en_US
dc.identifier.citationBiochemistry, 1976, v. 15 n. 20, p. 4537-4540en_US
dc.identifier.issn0006-2960en_US
dc.identifier.urihttp://hdl.handle.net/10722/167437-
dc.description.abstractThe binding and action of glucagon at its receptor in hepatic plasma membranes have been compared, as a function of pH, with that of glucagon containing iodotyrosyl residues. Iodinated glucagon, at pH 7.0 and below, binds to the receptor and activates adenylate cyclase with an affinity about threefold higher than that of native glucagon. At pH 8.5, the affinity of the receptor for native glucagon is the same as that seen at pH 7.0. However, iodinated glucagon binds with a lowered affinity with increasing pH. The decreased affinity of the iodinated hormone correlates with ionization of the iodotyrosyl phenoxy group, which has a pK a of 8.2. It is suggested that the decreased affinity is actually due to the inability of the ionized iodoglucagon to bind to the receptor. The relative potency of native and iodoglucagon will depend, therefore, on the concentrations of ionized and un-ionized species of iodoglucagon, which in turn depend on the pH of the medium. We conclude that incorporation of iodine atoms in the tyrosyl residues of glucagon has two major effects: (i) the iodine atom increases hydrophobic interaction of the hormone with the receptor and (ii) ionization of the phenoxy groups results in the loss of biological activity possibly as the result of loss of hydrogen bonding capability. Thus, the tyrosyl residues in glucagon are critically involved in the function of the hormone.en_US
dc.languageengen_US
dc.publisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/biochemistryen_US
dc.relation.ispartofBiochemistryen_US
dc.titleEffects of iodination of tyrosyl residues on the binding and action of glucagon at its receptoren_US
dc.typeArticleen_US
dc.identifier.emailLin, MC:mcllin@hkucc.hku.hken_US
dc.identifier.authorityLin, MC=rp00746en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1021/bi00665a031-
dc.identifier.pmid9975-
dc.identifier.scopuseid_2-s2.0-0017107926en_US
dc.identifier.volume15en_US
dc.identifier.issue20en_US
dc.identifier.spage4537en_US
dc.identifier.epage4540en_US
dc.identifier.isiWOS:A1976CF39300031-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLin, MC=7404816359en_US
dc.identifier.scopusauthoridNicosia, S=7102299447en_US
dc.identifier.scopusauthoridRodbell, M=7006658086en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats