W. Vangelder et al., ISOLATION AND PARTIAL CHARACTERIZATION OF 2 PORCINE SPLEEN FERRITIN FRACTIONS WITH DIFFERENT ELECTROPHORETIC MOBILITY, Comparative biochemistry and physiology. B. Comparative biochemistry, 115(2), 1996, pp. 191-199
Ferritin isolated from porcine spleen could routinely be separated in
two fractions on nondenaturating gradient gels. Both fractions could b
e isolated with a purity of 96% when applied to two serially linked co
lumns, each 200 cm in length, packed respectively with Sepharose 4B an
d Sepharose 6B. Both fractions were similar as judged by electron micr
oscopy. Assessed biochemically fractions were equal with respect ro su
bunit composition, iron and phosphorus content, as well as amino acid
composition (with the exception of N-acetylglucosamine). Carbohydrate
analysis showed that the fraction with an apparent mass of 440 kDa (=F
FL) contained 1.8% (w/w) glycans, whereas the fraction with an apparen
t mass of 670 kDa (=FFH) contained nearly five times as much (neutral)
sugar residues (8.9%, w/w) and 10 times as much sialic acid. This dif
ference in amount of carbohydrate side chains might explain the dissim
ilarity in electrophoretic mobility of the two fractions.