Separation of various calmodulins, calmodulin tryptic fragments, and different homologous Ca2+-binding proteins by reversed-phase, hydrophobic interaction, and ion-exchange high-performance liquid chromatography techniques

Reversed-phase, hydrophobic interaction, and ion-exchange high-performance liquid chromatography techniques have been used to separate different Ca2+-binding proteins and their proteolytic fragments. An alkali-stable ion-exchange column permitted the baseline separation of calmodulin fragments which differed only by one to three charged amino acids. The new hydrophobic interaction chromatography system displayed a high-resolution power separating calmodulins from different sources and calmodulin fragments obtained by trypsin proteolysis. The properties and advantages of the different systems are discussed in detail.