Subunit structure of canavalin

The subunit structure of canavalin was studied. The native protein has a sedimentation coefficient of 6.4 S and a MW of 91 000. SDS gel electrophoresis of the fully dissociated protein gave a single band, corresponding to a polypeptide chain with a MW of 22700. A minimal MW of 20700 was estimated from the amino acid composition. On a MW basis the native molecule consists of 4 chains. Support for the tetrameric structure of canavalin is provided by the electrophoretic pattern of partially dissociated protein.