Abstract: The invention provides a peptide capable of blocking voltage-gated K+ channels and inhibiting IL-2 production, which is represented by an amino acid sequence of: Ala-Ser-Cys-Arg-Thr-Pro-Lys-Asp-Cys-Ala-Asp-Pro-Cys-Arg-Lys-Glu-Thr-Gly-Cys-Pro-Tyr-Gly-Lys-Cys-Met-Asn-Arg-Lys-Cys-Lys-Cys-Asn-Arg-Cys; in which the C-terminal is amidated and four disulfide bridges are present in the molecule, and their related peptides isolated from the venom gland of a scorpion Heterometrus spinnifer. The peptides provided by the present invention are neuropeptides which can block voltage-gated K+ channels and inhibit IL-2 production at an extremely low concentration and, therefore, are expected to contribute to application of scorpion toxins to medicines and so on.

Abstract: Compounds represented by the general formula (I) or pharmacologically acceptable salts thereof: ##STR1## (where R is a group --NHCHR.sub.1 R.sub.2, --N(CHR.sub.1 R.sub.2).sub.2, --N(CHR.sub.1 R.sub.2)CHR.sub.3 R.sub.4, --N.sup.+ (CHR.sub.1 R.sub.2).sub.3, --N.sup.+ (CHR.sub.1 R.sub.2).sub.2 CHR.sub.3 R.sub.4 or --N.sup.+ (CHR.sub.1 R.sub.2)(CHR.sub.3 R.sub.4)CHR.sub.5 R.sub.6 (where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6, which may be the same or different, are each a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an aralkyl group, or an alkyl, alkenyl, aryl or aralkyl group which is substituted by at least one substituent selected from the group consisting of a halogen atom, a hydroxyl group, a lower alkoxy group, a lower alkylacyloxy group, a lower alkylacyl group, a lower alkoxycarbonyl group, a nitro group, a cyano group and a heterocyclic group, with CHR.sub.1 R.sub.2, CHR.sub.3 R.sub.4 or CHR.sub.5 R.sub.

Abstract: The metastasis of cells, which express a glycoprotein of human carcinoembryonic antigen on the cells surfaces, is inhibited in a living organ by administering, in advance, to a subject, a monoclonal antibody which binds a peptide which comprises at least the peptide sequence of domain N in the glycoprotein of human carcinoembryonic antigen.