[Crystallization of three multiple forms of transketolase from baker's yeast]

Three forms of baker's yeast transketolase have been revealed. These forms differed in thermal stability and elution profiles during chromatography on a phosphocellulose column and migrated with identical rates during electrophoresis in the presence of sodium dodecyl sulfate. The same forms in yeast, pig and rat liver and in different organs and tissues of the rabbit were found to be similar in their thermal stability and chromatographic properties. The relative amounts of the forms appeared to depend on the physiological state of the organism. Crystals of the three pure forms were grown using ammonium sulfate as the precipitating agent. These crystals differed morphologically and by stability upon storage. The possibility of interconversion of the transketolase forms is discussed.