Biological, immunological, and binding properties of recombinant mouse placental lactogen-I

Endocrinology. 1988 Dec;123(6):2662-7. doi: 10.1210/endo-123-6-2662.

Abstract

Mouse placental lactogen-I (mPL-I) cDNA was inserted into a eukaryotic expression vector and introduced into Chinese hamster ovary cells. Cell lines that secrete high concentrations of mPL-I were isolated, and this glycoprotein was purified from the cell culture-conditioned medium. Recombinant mPL-I (mPL-Ir) is very similar to placental mPL-I (mPL-Ip) in its recognition by polyclonal antisera raised against either mPL-Ip or mPL-Ir, in displacing [125I]iodo-mPL-II from binding sites on mouse liver microsomal membranes, and in stimulating the synthesis of alpha-lactalbumin in primary cultures of mouse mammary epithelial cells. Structural comparison of mPL-Ir and mPL-Ip by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that mPL-Ir comprises several proteins with mol wt ranging from 34.5-38K, while mPL-Ip consists of a similar set of proteins with mol wt ranging from 36.5-42K. Treatment of the two proteins with neuraminidase resulted in similar 2-4K decreases in mol wt. Treatment of mPL-Ip with peptide:N-glycosidase-F to remove asparagine-linked oligosaccharide chains resulted in the formation of 28K and 29K mol wt species, while treatment of mPL-Ir with the same enzyme yielded 28K and 28.5K mol wt products.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biological Assay
  • Cell Line
  • Cricetinae
  • DNA / genetics
  • Electrophoresis, Polyacrylamide Gel
  • Epithelium / metabolism
  • Lactalbumin / biosynthesis
  • Macromolecular Substances
  • Mammary Glands, Animal / drug effects
  • Mammary Glands, Animal / metabolism
  • Mice
  • Microsomes, Liver / metabolism
  • Molecular Weight
  • Placental Lactogen* / genetics
  • Placental Lactogen* / metabolism
  • Placental Lactogen* / pharmacology
  • Radioimmunoassay
  • Radioligand Assay
  • Recombinant Proteins* / genetics
  • Recombinant Proteins* / metabolism
  • Recombinant Proteins* / pharmacology
  • Transfection

Substances

  • Macromolecular Substances
  • Recombinant Proteins
  • DNA
  • Lactalbumin
  • Placental Lactogen