Stability and distribution of selenium associated with macromolecules in human milk

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5450522

Sherman-Martin, L; Milner, J A; Picciano, M F

Fresh milk samples from women residing in Illinois contained 14.4 +/- 1.6 (SEM) ng selenium per ml and had glutathione peroxidases (GPx) activities of 136.3 +/- 9.2 U (nmol NADPH oxidized/min/ml). After dialysis, in 10 mM Tris buffer (pH 7.6) which contained 1 mM GSH, 78% of the selenium and 35% of the GPx activity were retained. Freezing at -70/sup 0/C for four weeks did not significantly alter GPx activities or the percentage of selenium that was dialyzable. Skim milk contained 92 +/- 3.5% of the macromolecules associated with selenium could be identified between fresh and frozen milk partitioned with Sephacryl G-150 resin. A Sephadex G-100 column separated nondialyzed skim milk into two distinct fractions of macromolecules associated with selenium. However, dialyzed milk separated into at least four major fractions of macromolecules associated with selenium which corresponded to molecular weights of 15-20, 25-35, 65-70 and 85-150 KDal. In dialyzed milk, 50-90% of the selenium was associated with GPx or other macromolecules of 85 to 150 KDal. These data show that the major proportion of human milk selenium is bound to macromolecules and that freezing does not denature selenoproteins.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5450522
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEROXIDASES
ENZYME ACTIVITY
SELENIUM
TISSUE DISTRIBUTION
FREEZING
ILLINOIS
MAN
MILK
MOLECULAR WEIGHT
MOLECULES
ANIMALS
BIOLOGICAL MATERIALS
BODY FLUIDS
DISTRIBUTION
ELEMENTS
ENZYMES
FEDERAL REGION V
FOOD
MAMMALS
MATERIALS
NORTH AMERICA
OXIDOREDUCTASES
PRIMATES
SEMIMETALS
USA
VERTEBRATES
550500* - Metabolism