Abstract
The reaction of LATS activity with Staphylococcal Protein A, a specific binding protein with the Fc part of human IgG (1), IgG (2) and IgG (4), was examined. When IgG (1), IgG (2) and IgG (4) subclasses were removed from LATS positive sera or LATS-IgG fractions by affinity chromatography on Protein A-Sepharose, LATS activity decreased. Almost all LATS activity was found in the fraction that reacted with Protein A. It is suggested that LATS has an expression of a very distinct immunoglobulin G structure, and that LATS activity is distributed mainly in the fraction containing IgG (1), IgG (2) and IgG (4) in LATS positive serum.
