Sialosyllactotetraosylceramide, a novel ganglioside antigen detected in human carcinomas by a monoclonal antibody

Abstract

A novel ganglioside was detected in a small cell lung carcinoma by TLC-immunostaining of gangliosides with a monoclonal antibody, the C-50 MAb. Structural characterization showed this ganglioside to be IV³NeuAc-LcOse₄Cer, a hitherto unknown ganglioside. This ganglioside has also been detected as a minor component in many different carcinomas using the C-50 MAb. The normally dominant CA-50 ganglioside antigen is IV³NeuAc. III⁴Fuc-LcOse₄Cer. Based upon solid-phase binding to IV³NeuAc, III⁴-LcOse₄Cer and IV³NeuAc-LcOse₄Cer it is concluded that the C-50 MAb recognizes an epitope present in sialylated type I carbohydrate chains.