| 摘要 |
<p>New prepn. (I) has non-species-specific immunosuppressive activity. Also new are (a) a 'further purified' fraction and (b) a 'highly purified product', the characteristics of which are also specified below. (I) is characterised by certain of its chromatographic properties, and by the fact that it contains a "highly purified product" having the following properties: (a) substantially free from biologically inactive components, and separable from biologically active components by electrophoresis on a thin layer of cellulose in pyridine/acetic acid/acetone/water 1:2:8:40 (by volume) at pH 4.4 and 500V; (b) molecular weight below 5000; (c) wholly or partly peptide in nature; (d) detectable neither with ninhydrin- collidine nor fluorescamine in thin layer; (e) N-terminal blocked with a pyroglutamyl residue; (f) C-terminal either lysine or arginine; (g) inactivated by pronase, trypsin, pyroglutamate aminopeptidase, carboxypeptidases A and B; (h) not inactivated by leucine aminopeptidase, chymotrypsin, DNA-ase or 10A-ase;(i)specific,reversibleaffinityforIgG;(j)no selective affinity for IgM; (k) inhibits in vitro and in-vivo the formation of IgM- and IgG-carrying cells; (l) non-cytotoxic to lymphocyte cultures; (m) inhibits allogenic transplant reactions; (n) does not markedly influence spleen function in the mouse; (o) substantially free from inhibitory action on independent T antigens; (p) does not inhibit in vitro incorporation of tritiated-thymidine by mitogen-stimulated spleen lymphocyte cultures. The "further purified fraction" is characterised by its elution time under specified high pressure chromatography conditions. The new prepn. and prods. have considerable immunosuppressive activity and can be used as comparative standards for evaluation of the immunosuppressive action of investigative substances.</p> |
