Re‐evaluation of the whey protein/casein ratio of human milk

Wiley - Tập 81 Số 2 - Trang 107-112 - 1992
Silvia Rudloff1, Bo Lönnerdal1
1Department of Nutrition, University of California, Davis, CA USA.

Tóm tắt

Total casein subunits as well as whey proteins were quantitated in human milk samples during lactation. Two independent methods were used: precipitation at pH 4.3 in the presence of Ca2+ followed by Kjeldahl analysis and polyacrylamide gradient gel electrophoresis (PAGGE) followed by densitometric scanning. Both methods yielded similar results: casein synthesis is low or absent in early lactation, then increases rapidly and subsequently decreases. The concentration of whey proteins decreases from early lactation and continues to fall. These changes result in a whey protein/casein ratio of about 90: 10 in early lactation, 60: 40 in mature milk and 50: 50 in late lactation. These observations indicate that the synthesis and/or secretion of caseins and whey proteins is regulated by different mechanisms. In addition, the relative proportion of the different β‐ and k‐casein subunits was found to vary throughout lactation.

Từ khóa


Tài liệu tham khảo

10.1017/S0022029900002302

10.3168/jds.S0022-0302(74)85030-7

10.1271/bbb1961.48.771

10.1017/S0022029900024109

Kunz C, 1989, Human milk proteins: separation of whey proteins and their analysis by polyacrylamide gel electrophoresis, fast protein liquid chromatography (FPLC) gel filtration, and anion‐exchange chromatography, Am J Clin Nutr, 49, 464, 10.1093/ajcn/49.3.464

10.1016/S0021-9673(01)92580-4

10.1016/0005-2795(72)90036-0

Lönnerdal B, 1985, Casein content of human milk, Am J Clin Nutr, 41, 113, 10.1093/ajcn/41.1.113

10.1093/ajcn/51.1.37

10.1042/bj0910130

Montgomery PA, 1987, Gel electrophoretic analysis of proteins in human milk and colostrum, Comp Biochem Physiol, 86, 635

10.1016/0003-2697(76)90508-X

Dische Z., 1962, Methods in carbohydrate chemistry, 488

10.1016/0006-3002(57)90254-8

10.1016/0003-2697(69)90372-8

10.1042/bj2420735

10.1021/bi00595a016

RosenJM MedinaD SchleinAR EisensteinRS Yu‐LeeL.Hormonal and cell‐substratum regulation of casein gene expression at the posttranscriptional level. Steroid Hormone Action 269–78.

Picone TA, 1988, Protein and non‐protein nitrogen in human milk, 173

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Thông tin xuất bản

Wiley

Tập 81 Số 2

107-112

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