Identification of HSP-60 as the specific antigen of IgM produced by BRG-lymphoma cells

In previous studies we described a patient with Burkitt's lymphoma and AIDS , whose cells recognized a molecule expressed by normal and malignant breas t cells. In the present study, we identified this antigen by two-dimensiona l (2-D) electrophoresis and Western blotting using the antibody produced by lymphoma cells. The antigen so identified consisted of two clusters of spo ts with a molecular mass (M-r) of 60 and 50 kDa, respectively. Preparative immobilized pH gradient (IPG) was subsequently used to isolate the clusters of spots of higher molecular masses, from which peptide fragments of appro ximately 10 aa were separated on reverse-phase chromatography and sequenced . This procedure enabled the identification of the antigen recognized by th e lymphoma cells as HSP-60. By means of serological analyses it was possibl e to identify the lower molecular mass cluster of spots as a molecule relat ed to HSP-60. It is hypothesized that this molecule is a membrane form of H SP-60 that differs from HSP-60 in a COOH terminal portion.