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PubMed · 1694776

Guanine nucleotides decrease the affinity of substance P binding to its receptor.

J Luber-Narod·N D Boyd·S E Leeman
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Abstract

The inhibitory effect of guanine nucleotides on the binding of 125I-Bolton-Hunter conjugated substance P (125I-BHSP) to rat submaxillary gland membranes has been confirmed and further explored. The evidence presented here indicates that this is due to a marked loss of binding affinity. In the presence of 5'-guanylyl imidodiphosphate (GppNHp) there is (1) a greater than or equal to 20-fold increase in the Kd as determined by Scatchard analysis and (2) the concentration of SP required to inhibit half of the 125I-BHSP binding (IC50) increased approximately 30-fold. Consistent with a marked decrease in affinity is an approximately 100-fold increase in the rate of dissociation of 125I-BHSP following addition of GppNHp. Complete restoration of high-affinity binding was achieved by removal of the guanine nucleotide.

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Guanine NucleotidesGuanylyl ImidodiphosphateIndicators and ReagentsIodine RadioisotopesKineticsMembranesReceptors, Neurokinin-1Receptors, NeurotransmitterSubmandibular GlandSubstance PSuccinimidesJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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J Luber-Narod, N D Boyd, S E Leeman. 1990-04-25. Guanine nucleotides decrease the affinity of substance P binding to its receptor.. https://doi.org/10.1016/0922-4106(90)90001-e

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