Recombinant Human Placental Lactogen/CSH1 Protein

• Reactivity: Hu
• Applications: Bioactivity

Recombinant Human Placental Lactogen/CSH1 Protein Summary

• Details of Functionality: Measured in a cell proliferation assay using Nb2‑11 rat lymphoma cells. Gout, P.W. et al. (1980) Cancer Res. 40:2433. The ED₅₀ for this effect is 0.1-0.5 ng/mL
• Source: Chinese Hamster Ovary cell line, CHO-derived human Placental Lactogen/CSH1 protein
  Val27-Phe217 with a C-terminal 6-His tag
• Accession #: P01243
• N-terminal Sequence: Val27
• Protein/Peptide Type: Recombinant Proteins
• Gene: CSH1
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 23.1 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 24 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein.
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Reconstitution Instructions: Reconstitute at 100 μg/mL in PBS containing at least 0.1% human or bovine serum albumin.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Placental Lactogen/CSH1 Protein

• Choriomammotropin
• chorionic somatomammotropin hormone 1 (placental lactogen)
• chorionic somatomammotropin hormone
• CS-1
• CSAchorionic somatomammotropin A
• CSH1
• CSH2
• CSMT
• FLJ75407
• hCS-A
• Lactogen
• PL
• Placental Lactogen
• PLchoriomammotropin

Background

Human Placental Lactogen (abbreviated PL or hPL), also called chorionic somatomammotropin hormone 1 (abbreviated CSH1), is a member of the prolactin/growth hormone (PRL/GH) family (1). It is found in a cluster of growth hormones on chromosome 17 that appear to have a common ancestry. Identical 191 amino acid (aa) mature hPL proteins may be formed from one of two genes (2). PL contains a pair of C-terminal cysteines that may form either intra- or interchain disulfides. Human PL shares 98% aa identity with chimpanzee PL and >85% aa sequence identity with other human growth hormones, but only ~25% aa identity with mouse, ovine or bovine PL. PL is mainly expressed by cells in the syncytiotrophoblast layer of the placenta, which produce increasing amounts of PL as pregnancy proceeds. The major portion enters the maternal circulation, where it joins GH2 (placenta-specific GH) in replacing the functions of pituitary GH during pregnancy. A smaller amount of PL circulates in the fetus. Primate PL shows high affinity for the PRL receptor and low affinity for the GH receptor (1). Reduced stimulation of PL by angiotensin 2 correlates with intrauterine growth restriction (3). There is some evidence that mature angiogenic PL may be cleaved to form an anti-angiogenic N-terminal fragment (4). Although PL promotes pancreatic beta cell survival, it does not appear to be altered in gestational diabetes. It helps prepare mammaries for lactation, but probably does not influence lactation itself. PL may be a ligand of stabilin-1, which has been proposed to regulate PL internalization and degradation or re-expression (6).

1. Handwerger, S. and M. Freemark (2000) J. Ped. Endocrinol. Metab. 13:343.
2. Selby, M.J. et al. (1984) J. Biol. Chem. 259:13131.
3. Szukiewicz, D. et al. (2008) Int. Immunopharmacol. 8:177.
4. Struman, I. et al. (1999) Proc. Natl. Acad. Sci. USA 96:1246.
5. Fujinaka, Y. et al. (2007) J. Biol. Chem. 282:30707.
6. Kzhyshkowska, J. et al. (2008) J. Immunol. 180:3028.

Bioinformatics

• Gene Symbol: CSH1
• Uniprot:
  • P01243(Human)