Abstract: Oligopeptides having an amino acid sequence corresponding to a receptor's extracellular domain, and having sequence similarity to regulatory peptides from MHC class I antigens, enhance the physiological response of ligand binding to the corresponding receptor. The oligopeptides are used in diagnosis and therapy of diseases that involve inadequate or inappropriate receptor response as well as in the screening of drug candidates that affect surface expression of receptors. Also useful for drug screening is a modified receptor molecule, where the sequence corresponding to the regulatory peptide is modified or deleted.

Abstract: Oligopeptides having an amino acid sequence corresponding to a receptor's extracellular domain, and having sequence similarity to regulatory peptides from MHC class I antigens, enhance the physiological response of ligand binding to the corresponding receptor. The oligopeptides are used in diagnosis and therapy of diseases that involve inadequate or inappropriate receptor response as well as in the screening of drug candidates that affect surface expression of receptors. Also useful for drug screening is a modified receptor molecule, where the sequence corresponding to the regulatory peptide is modified or deleted.

Abstract: Methods and compositions are provided for regulating surface membrane receptor response by providing novel proteinaceous compositions to bind to two separate sites of a surface membrane receptor, the binding site of the receptor and an allosteric site, which binds to a sequence of a Class I MHC antigen. The resulting products may act as agonist or antagonist to the normal function of the receptor and find use in the control of physiological processes.