Follistatin

Follistatin 344 1mg

Follistatin (FST) is a secreted glycoprotein that was first identified as a follicle­stimulating hormone inhibiting substance in ovarian follicular fluid (1, 2). Human Follistatin cDNA encodes a 344 amino acid (aa) protein with a 29 aa signal sequence, an N­terminal atypical TGF binding domain, three Follistatin domains that contain EGF­like and kazal­like motifs, and a highly acidic C­terminal tail. Follistatin is a secreted protein that binds to ligands of the TGF-Beta family and regulates their activity by inhibiting their access to signaling receptors. It was originally discovered as activin antagonists whose activity suppresses expression and secretion of the pituitary hormone FSH (follicle stimulating hormone). In addition to being a natural antagonist, follistatin can inhibit the activity of other TGF-Beta ligands including BMP-2,-4,-6,-7, Myostatin, GDF-11, and TGF-Beta1. Follistatin is expressed in the pituitary, ovaries, decidual cells of the endometrium, and in some other tissues. Recombinant human Follistatin is a 37.8 kDa protein containing 344 amino acids.

synonyms

 

FST, FS, Activin-binding protein.

 

 

 

Introduction

 

Follistatin (FS) was initially identified as a follicle-stimulating hormone inhibiting substance found in ovarian follicular fluid. FS is a high-affinity activin-binding protein that can act as an activin antagonist. Two alternatively spliced follistatin mRNAs exist, encoding mature FS with 288 amino acid (aa) residues (FS-288) and 315 aa residues (FS-315). Natural FS purified from porcine ovaries is primarily a carboxy-terminal truncated form of FS-315 composed of 300 aa residues.

Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. The single FST gene encodes two isoforms, FST317 and FST344 containing 317 and 344 amino acids respectively, resulting from alternative splicing of the precursor mRNA. In a study in which 37 candidate genes were tested for linkage and association with polycystic ovary syndrome (PCOS) or hyperandrogenemia in 150 families, evidence was found for linkage between PCOS and follistatin. Follistatin binds directly to activin and functions as an activin antagonist. specific inhibitor of the biosynthesis and secretion of pituitary follicle stimulating hormone (fsh).

Description

 

Follistatin Human Recombinant produced in E.Coli is a single, non-glycosylated polypeptide chain containing 288 amino acids and having a total molecular mass of 31.5kDa.
The FST is purified by proprietary chromatographic techniques.

Source

 

Escherichia Coli.

Physical Appearance

 

Sterile Filtered White lyophilized (freeze-dried) powder.

Formulation

 

Lyophilized from a concentrated (1mg/ml) solution containing no additives.

Solubility

 

It is recommended to reconstitute the lyophilized Follistatin in sterile 18MΩ-cm H2O not less than 100µg/ml, which can then be further diluted to other aqueous solutions.

Stability

 

Lyophilized Follistatin although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution FST should be stored at 4°C between 2-7 days and for future use below -18°C.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please prevent freeze-thaw cycles.

Purity

 

Greater than 99.0% as determined by:

 

Greater than 99.0% as determined by:(a) Analysis by RP-HPLC.
(b) Analysis by SDS-PAGE.

Amino acid sequence

 

The sequence of the first five N-terminal amino acids was determined and was found to be Gly-Asn-Cys-Trp-Leu.

Biological Activity

 

The activity is determined by the ability to neutralize Activin A inhibitory effect of mouse MPC-11 cells. The expected ED50 is 0.1-0.4 µg/ml in the presence of 7.5 ng/ml Activin A.

Usage

 

ProSpec’s products are furnished for LABORATORY RESEARCH USE ONLY.They may not be used as drugs,agricultural or pesticidal products, food additives or household chemicals.