Bidlack J M, O'Malley W E
J Biol Chem. 1986 Dec 5;261(34):15844-9.
Fab fragments from a monoclonal antibody, OR-689.2.4, directed against the opioid receptor, selectively inhibited opioid binding to rat and guinea pig neural membranes. In a titratable manner, the Fab fragments noncompetitively inhibited the binding of the mu selective peptide [D-Ala2,(Me)Phe4,Gly(OH)5][3H] enkephalin and the delta selective peptide [D-Pen2,D-Pen5] [3H]enkephalin (where Pen represents penicillamine) to neural membranes. In contrast, kappa opioid binding, as measured by the binding of [3H]bremazocine to rat neural membranes and guinea pig cerebellum in the presence of mu and delta blockers, was not significantly altered by the Fab fragments. In addition to blocking the binding of mu and delta ligands, the Fab fragments displaced bound opioids from the membranes. When mu sites were blocked with [D-Ala2,(Me)Phe4,Gly(OH)5]enkephalin, the Fab fragments suppressed the binding of [D-Pen2,D-Pen5][3H]enkephalin to the same degree as when the mu binding site was not blocked. The Fab fragments also inhibited binding to the mu site regardless of whether or not the delta site was blocked with [D-Pen2,D-Pen5]enkephalin. This monoclonal antibody is directed against a 35,000-dalton protein. Since the antibody is able to inhibit mu and delta binding but not kappa opioid binding, it appears that this 35,000-dalton protein is an integral component of mu and delta opioid receptors but not kappa receptors.
一种针对阿片受体的单克隆抗体OR-689.2.4的Fab片段，可选择性抑制阿片与大鼠和豚鼠神经膜的结合。Fab片段以可滴定的方式非竞争性抑制μ选择性肽[D-Ala2，(Me)Phe4，Gly(OH)5][3H]脑啡肽和δ选择性肽[D-Pen2，D-Pen5][3H]脑啡肽（其中Pen代表青霉胺）与神经膜的结合。相比之下，在存在μ和δ阻滞剂的情况下，通过[3H]布托啡诺与大鼠神经膜和豚鼠小脑的结合来测量的κ阿片结合，并未因Fab片段而发生显著改变。除了阻断μ和δ配体的结合外，Fab片段还能将结合的阿片从膜上置换下来。当用[D-Ala2，(Me)Phe4，Gly(OH)5]脑啡肽阻断μ位点时，Fab片段抑制[D-Pen2，D-Pen5][3H]脑啡肽结合的程度与未阻断μ结合位点时相同。无论δ位点是否用[D-Pen2，D-Pen5]脑啡肽阻断，Fab片段也能抑制与μ位点的结合。这种单克隆抗体针对的是一种35000道尔顿的蛋白质。由于该抗体能够抑制μ和δ结合，但不能抑制κ阿片结合，看来这种35000道尔顿的蛋白质是μ和δ阿片受体的一个组成部分，而不是κ受体的组成部分。
