Abstract: Methods and compositions are provided for regulating surface membrane receptor responses by modulating interaction between MHC Class I antigen and the surface membrane receptor. Various techniques may be employed for enhancing or reducing the interaction between the MHC Class I antigen and surface membrane receptor (e.g., enhancing surface expression of the MHC Class I antigen or employing agents which affect interaction between MHC Class I antigen and surface receptors). The aggregative characteristics of oligopeptides which act as agents in affecting interaction between MHC Class I antigen and surface receptors may be employed in a screening assay for determining drugs which affect interaction between Class I antigen and surface receptors. Active peptide aggregative characteristics may also be employed in a method of administration of effectors of surface receptor response modulation.

Abstract: Methods and compositions are provided for regulating surface membrane receptor responses by modulating interaction between MHC Class I antigen and the surface membrane receptor. Various techniques may be employed for enhancing or reducing the interaction between the MHC Class I antigen and surface membrane receptor (e.g., enhancing surface expression of the MHC Class I antigen or employing agents which affect interaction between MHC Class I antigen and surface receptors). The aggregative characteristics of oligopeptides which act as agents in affecting interaction between MHC Class I antigen and surface receptors may be employed in a screening assay for determining drugs which affect interaction between Class I antigen and surface receptors. Active peptide aggregative characteristics may also be employed in a method of administration of effectors of surface receptor response modulation.

Abstract: Methods and compositions are provided for regulating surface membrane receptor responses, where the surface membrane receptor is a glucose transporter, by modulating interaction between MHC Class I antigen and the surface membrane receptor. Various techniques may be employed for enhancing or reducing the interaction between the MHC Class I antigen and surface membrane receptor (e.g., enhancing surface expression of the MHC Class I antigen or employing agents which affect interaction between MHC Class I antigen and surface receptors). The aggregative characteristics of oligopeptides which act as agents in affecting interaction between MHC Class I antigen and surface receptors may be employed in a screening assay for determining drugs which affect interaction between Class I antigen and surface receptors. Active peptide aggregative characteristics may also be employed in a method of administration of effectors of surface receptor response modulation.

Abstract: Novel opioid compounds are provided having a phenolic hydroxyl and a pentet of alternating basic hydrophilic and hydrophobic groups derived from basic amino acids and hydrophobic amino acids. Desirably, the pentet, usually sextet, is separated from the phenolic ring by at least about 3 atoms in a chain, preferably at least about 15 atoms in a chain and not more than about 30 atoms in a chain (for rings one will take the average of the shortest and longest distances). Particularly, a polypeptide is provided having tyrosyl at the amine end, desirably as the first amino acid of leu- or met-enkephalin and a sextet of alternating basic hydrophilic and hydrophobic amino acids spaced from the enkephalin by at least about one amino acid. Desirably, the polypeptide is at least 1,200 molecular weight and under about 2,500 molecular weight.

Abstract: Compounds are provided for use in assays of organic compounds, where organic compounds of biological interest are determined at extremely low concentrations by combining in a medium, the composition to be determined, hereinafter referred to as ligand, a high molecular weight material of at least 10,000 molecular weight, which has a site spatially characteristic of the ligand, hereinafter referred to as receptor, and an analog of the ligand having a free radical functionality, hereinafter referred to as "ligand analog". The ligand analog and ligand in the medium compete for the receptor site, the amount of ligand analog bound to the receptor, being dependent on the amount of ligand present in the medium. By following the change in electron spin resonance spectrum of the ligand analog and comparing it to the change in spectrum which would be obtained in the absence of any ligand, the amount of ligand can be determined.

Abstract: Compounds are provided for use in assays of organic compounds, where organic compounds of biological interest are determined at extremely low concentrations by combining in a medium, the composition to be determined, hereinafter referred to as ligand, a high molecular weight material of at least 10,000 molecular weight, which has a site spatially characteristic of the ligand, hereinafter referred to as receptor, and an analog of the ligand having a free radical functionality, hereinafter referred to as "ligand analog". The ligand analog and ligand in the medium compete for the receptor site, the amount of ligand analog bound to the receptor, being dependent on the amount of ligand present in the medium. By following the change in electron spin resonance spectrum of the ligand analog and comparing it to the change in spectrum which would be obtained in the absence of any ligand, the amount of ligand can be determined.

Abstract: Compounds are provided for use in assays of organic compounds, where organic compounds of biological interest are determined at extremely low concentrations by combining in a medium, the composition to be determined, hereinafter referred to as ligand, a high molecular weight material of at least 10,000 molecular weight, which has a site spatially characterisitc of the ligand, hereinafter referred to as receptor, and an analog of the ligand having a free radical functionality hereinafter referred to as "ligand analog". The ligand analog and ligand in the medium compete for the receptor site, the amount of ligand analog bound to the receptor, being dependent on the amount of ligand present in the medium. By following the change in electron spin resonance spectrum of the ligand analog and comparing it to the change in spectrum which would be obtained in the absence of any ligand, the amount of ligand can be determined.