Abstract: The present invention provides a method of selecting an IL-2 production inhibitor and/or an immunocyte proliferation inhibitor having low GATA-1 production inhibitory activity, which comprises measuring the HDAC4 and/or HDAC8 inhibitory activity of a test substance, and a method of selecting an immunosuppressant having low thrombocytopenic activity, which comprises measuring the HDAC4 and/or HDAC8 inhibitory activity of a test HDAC inhibitor.

Abstract: A cyclic tetrapeptide compound of the formula (I): wherein R1 is hydrogen; R2 is lower alkyl, aryl, optionally substituted ar(lower)alkyl, heterocyclic(lower)alkyl, cyclo(lower)alkyl(lower)alkyl, lower alkylcarbamoyl(lower)alkyl or arylcarbamoyl(lower)alkyl; R3 and R4 are each independently hydrogen, lower alkyl, optionally substituted ar(lower)alkyl, optionally substituted heterocyclic(lower)alkyl or cyclo(lower)alkyl(lower)alkyl, or R3 and R4 are linked together to form lower alkylene or condensed ring, or one of R3 and R4 is linked to the adjacent nitrogen atom to form a ring; R5 is lower alkylene or lower alkenylene, Y is [wherein RY1 is hydrogen, halogen or optionally protected hydroxy, RY2 is hydrogen, halogen, lower alkyl or phenyl, and RY3 is hydrogen or lower alkyl]; R8 is hydrogen or lower alkyl; and n is an integer of 1 or 2, or a salt thereof.

Abstract: The invention relates to a novel method for selecting an immunosuppressive agent with a less thrombocytopenia effect. According to the invention, a method for selecting an immunosuppressive agent which has a potent immunosuppressive activity but a lower thrombocytopenia effect, said method comprising measuring an IL-2 transcription inhibitory activity in a test cell in to which an IL-2 reporter gene has been introduced in the coexistence of an analyte, while measuring a GATA-1 transcription inhibitory activity in the test cell into which a GATA-1 reporter gene has been introduced in the coexistence of an analyte, and comparing both the transcription inhibitory activities, is provided.

Abstract: A mutant CC acylase wherein at least one amino acid at the Ala.sup.49, Met.sup.164, Ser.sup.166, Met.sup.174, Glu.sup.358, Met.sup.465, Met.sup.506, or Met.sup.750 position of the amino acid sequence of the native CC acylase is replaced by a different amino acid, a DNA coding therefor, an expression vector containing the said DNA, a microorganism transformed with the said expression vector, the production of the CC acylase by culturing the said transformant, and use thereof for the production of a compound. The mutant CC acylase of the invention has desirable properties in terms of enzymatic potency, alteration of pH profile, efficiency of processing, and the like.