Binding of glycoglycerolipid derived from membranes of Acholeplasma laidlawii PG8 and synthetic analogues to lymphoid cells

A component that binds to human lymphoid cells was isolated from the membra nes of Acholeplasma laidlawii PG8. The component was extracted using the Bl igh-Dyer method and purified using a silica-gel column and TLC. The active component was identified as 3-O-[2'-O-(alpha-D-glucopyranosyl)-6'-O-acyl-al pha-D-glucopyranosyl]-1,2-di-O-acyl-sn-glycerol (CACDG) using H-1- and C-13 -NMR and GC-MS. The compositions of the major saturated fatty acids were nC (14) (17.8%), isoC(14) (10.7 %) and nC(16) (34(.)9%) as determined by GC-MS . The amounts of unsaturated species were less than 10% of those of the cor responding saturated acids. GAGDCs which have three tetradecanoyl groups we re synthesized. These synthetic GAGDCs, as well as GAGDGs derived from A. l aidlawii membranes, had a high binding affinity for MOLT-4 and HUT-78 (huma n T cell lines), Raji (a B cell line), HL-60 (a monoblastoid cell line) and primary cultured human T cells. The binding affinities of GAGDGs with an i soC(14) acyl group was higher than those with nC(14) and nC(16) acyl groups . The binding to lymphoid cells reveals a novel biological activity of GAGD Cs.