Purity
>95%, by SDS-PAGE under reducing conditions and visualized by silver stain
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method.
Activity
Measured in a cell proliferation assay using Nb2‑11 rat lymphoma cells. Gout, P.W. et al. (1980) Cancer Res. 40:2433. The ED 50 for this effect is 0.1-0.5 ng/mL
Source
Chinese Hamster Ovary cell line, CHO-derived Val27-Phe217 with a C-terminal 6-His tag
Accession #
N-terminal Sequence
AnalysisVal27
Predicted Molecular Mass
23.1 kDa
SDS-PAGE
24 kDa, reducing conditions
Carrier Free
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.
5757-PL |
| 5757-PL/CF |
Formulation Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein. | Formulation Lyophilized from a 0.2 μm filtered solution in PBS. | |
Reconstitution Reconstitute at 100 μg/mL in PBS containing at least 0.1% human or bovine serum albumin. | Reconstitution Reconstitute at 100 μg/mL in PBS. | |
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | |
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
| Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
|
Background: Placental Lactogen/CSH1
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).
References:
Handwerger, S. and M. Freemark (2000) J. Ped. Endocrinol. Metab. 13:343.
Selby, M.J. et al. (1984) J. Biol. Chem. 259:13131.
Szukiewicz, D. et al. (2008) Int. Immunopharmacol. 8:177.
Struman, I. et al. (1999) Proc. Natl. Acad. Sci. USA 96:1246.
Fujinaka, Y. et al. (2007) J. Biol. Chem. 282:30707.
Kzhyshkowska, J. et al. (2008) J. Immunol. 180:3028.
Entrez Gene IDs:
1442 (Human)
Alternate Names:
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
