A comparison of microsomal and synaptic delta site binding kinetics.
High-affinity binding of the agonist, [3H]D-ala2-D-leu5-enkephalin (DADLE), to delta sites on bovine hippocampal synaptic plasma membranes (SPM) entails a multi-step association process. Microsomal binding sites, which are thought to originate from internal membranes (golgi, ser, etc.), display kinetic patterns that differ from SPMs. This is evidenced by the absence of an association time dependent rate of dissociation from microsomal binding sites. Although high affinity steady state binding of agonists to microsomes occurs, kinetic analysis indicates little or no formation of the high affinity slowly dissociating complex. This slowly dissociating complex of SPMs is most sensitive to guanine nucleotides. Consequently, the effect of Gpp(NH)p on dissociation is significantly less for microsomes.
Spain
J W
JW
E.A. Doisy Department of Biochemistry, St. Louis University School of Medicine, MO 63104.
Petta
D E
DE
Coscia
C J
CJ
D000818:Animals; D002417:Cattle; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D006624:Hippocampus / Q000378:metabolism*; D007700:Kinetics; D008861:Microsomes / Q000378:metabolism*; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D013570:Synaptic Membranes / Q000378:metabolism*
D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine