Sulfoethyl-sephadex

Cation-exchange columns have been used effectively by some investigators for the fractionation of casein (Annan and Manson 1969 Kim et al 1969 Kopfler et al. 1969 Snoeren et al. 1977 Saito et al 1979). Sulfoethyl-Sephadex was used by Annan and Manson (1969) with formate buffer to fractionate the as-casein complex. Cellulose phosphate, carboxyl-methyl-cellulose (CMC), potassium-K-carrageenan, and sodium Amberlite CG50 columns have also been used to fractionate the caseins (Kim et al. 1969 Kopfler et al. 1969 Snoeren et al 1977). A batch method for the preparation of para-K-casein from rennin-treated whole casein has been developed with CMC Sephadex (Saito et al. 1979). 

Fructose diphosphatase has also been purified from acetone powders of rabbit kidney (63) by acid precipitation, ammonium sulfate precipitation, heating at pH 4.5, and chromatography on phosphocellulose, and sulfoethyl Sephadex. This preparation, which was homogeneous in gel electrophoresis, was employed for the immunological studies described earlier. 

This procedure has the advantage of separating LH and FSH from impurities on the basis both of charge and of size of molecules. Papkoff et al. employed sulfoethyl Sephadex C-50 to separate both ovine and human FSH from contaminants, and then passed the human FSH through carboxymethyl Sephadex C-50 in the final step of their purification procedure (P4, P5). Papkoff et al. and Roos also used sulfoethyl Sephadex C-50 to purify human LH (P6, R15). 

Although pure bovine mercaptalbumin prepared by chromatography on sulfoethyl Sephadex C-50 was found to be more homogeneous than parent BSA as shown by its solubility-pH profile and solubility behavior in concentrated ammonium sulfate solutions, it did not yield separate N and F boundaries on electrophoresis however, it exhibited heterogeneity with respect to binding with detergents, and two components were resolvable by electrophoresis (Hagenmaier and Foster, 1971). 

For cation-exchanging Sephadex, SE-, SP- and CM-sephadex, having sulfoethyl, sulfopropyl, and carboxysKthyl groups respectively, are available. SE-Se dex can be replaced by SP-Sephadex both have almost the same phyacal and chonical u operties. 

---