Analysis of a surface antigen of Pneumocystis carinii.

The 115 kd band in polyacrylamide gels is a major antigen of Pneumocystis carinii. Data obtained from treatment with enzymes, binding to lectins, and labelling the surface with biotin suggest that this moiety is a glycoprotein containing mannosyl/glucosyl and N-acetylglucosamine residues, and that it is located on the cell wall of the organism. Other rat and human P. carinii antigens also are glycoproteins but differ in specific protein or carbohydrate residues or location on the organism.