Preparation and characterization of the major isotype of parvalbumin from skeletal muscle of the toad ( XXXX ).

@entity1025 @entity2228 @entity535 @entity27917 @entity2975 @entity141 @entity815 @entity214
The major isotype of parvalbumin has been isolated from the skeletal muscle of the toad, @entity27917 . Unlike the skeletal muscle of every frog so far examined (Rana esculenta, Rana temporaria, and Rana catesbeiana), which contains two major isotypes of parvalbumins, toad skeletal muscle has been shown to contain only one isotype, but the content of parvalbumin in toad skeletal muscle was similar to the sum of those of the two isotypes in skeletal muscles of frogs. This feature of toad skeletal muscle is advantageous to clarify the physiological role of parvalbumin. The relative molecular mass of toad parvalbumin was estimated to be 12,200 by @entity214 - @entity2975 gel electrophoresis. The isoelectric point was determined to be 4.81 by @entity2975 gel isoelectric focusing. The @entity535 composition indicated that toad parvalbumin corresponds to bullfrog (R. catesbeiana) pI 4.97 parvalbumin, showing that toad parvalbumin is genetically an alpha-parvalbumin. It was also revealed by the @entity535 composition that toad parvalbumin is distinctly different from any of the parvalbumins from frogs. The ultraviolet spectrum of toad parvalbumin is consistent with its @entity535 composition. The ultraviolet difference spectrum of the @entity141 -loaded form vs. the metal-free form indicates that some @entity815 residues in the toad parvalbumin molecule are affected by a conformational change associated with @entity141 binding. On electrophoresis in @entity2975 gel in 14 mM Tris and 90 mM @entity2228 , the metal-free and @entity1025 -loaded forms of toad parvalbumin migrated twice as fast as the @entity141 -loaded form.(ABSTRACT TRUNCATED AT 250 WORDS)
