Protein Laboratories Rehovot Ltd.
May 2019

Certificate of Analysis & Data Sheet

We are the ONLY company producing leptin antagonists and leptins of farm animals including several fish species.

Pegylated human, mouse, rat and ovine leptins and corresponding leptin antagonists are now available!!!

PLR provides a novel service of pegylation of either existing, or provided or custom-made proteins. All PLR's proteins are carrier free (cf) and can be sold in any requested amount !!!
Horse leptin - Cat no. LEP-4 GENE ID 100034042
Description: Recombinant horse leptin is an one polypeptide chain containing 146 amino and additional Ala at N-terminus acids and having a molecular mass of ~ 16 kDa. Recombinant horse leptin was purified by proprietary chromatographic techniques, (unpublished). 
Source: E. coli 
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Physical Appearance: White lyophilized (freeze-dried) powder. 
Formulation: The recombinant protein was lyophilized from a concentrated (1mg/ml) solution with 0.0045mM NaHCO3.
Solubility: It is recommended to reconstitute the lyophilized recombinant horse leptin in sterile water or 0.4% NaHCO3 adjusted tp pH 8-9, not less than 100µg/ml, which can then be further diluted to other aqueous solutions. 
Stability: Lyophilized recombinant horse leptin although stable at room temperature for several weeks, should be stored desiccated below -18C. Upon reconstitution at > 0.1 recombinant horse leptin mg/ml and up to 2 mg and filter sterilization recombinant horse leptin can be stored at +4C. 
Purity: The purity of recombinant horse leptin is greater than 99.0% as determined by:
(a) Gel filtration analysis.
(b) Analysis by reducing and non-reducing SDS-PAGE gel. 
Amino Acid Sequence: The sequence of the first five N-terminal amino acids of recombinant horse leptin was determined and was found to be Ala-Val-Pro-Ile-Gln 
Dimers and Aggregates: The purified racombinant horse leptin (16K) consists of > 97% monomers as determined by gel-filtration chromatography.
Biological Activity: PLR’s recombinant horse leptin is fully biologically active as evidenced by inducing proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor. 
Endotoxin: The endotoxin content of recombinant horse leptin is less than 0.1 ng/µg (IEU/µg) of horse leptin 
Protein content: Protein quantitation of recombinant horse leptin was carried out by UV spectroscopy at 280 nm using the absorbency value of 0.20 as the extinction coefficient for a 0.1% (1mg/ml) solution at pH 8.0. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). 
Usage: This recombinant horse leptin is offered by PLR for laboratory research 
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