Protein Laboratories Rehovot Ltd.
Human leptin - Cat no. LEP-5 GENE ID 3952
Description:
Recombinant protein - human leptin, one polypeptide chain containing 146 amino and additional Ala at N-terminus acids and having a molecular mass of ~ 16 kDa., Human leptin was purified by proprietary chromatographic techniques, see Raver et al. Gen. Comp. Endocrinol. (2002).
Source:
Escherichia coli
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 human leptin in sterile water or 0.4% NaHCO3 adjusted to pH 8-9, not less than 100µg/ml, which can then be further diluted to other aqueous solutions.
Stability:
Lyophilized recombinant human leptin although stable at room temperature for several weeks, should be stored desiccated below -18C. Upon reconstitution at > 0.1 human leptin mg/ml and up to 2 mg and filter sterilization recombinant human leptin can be stored at +4C or even room temperature for several weeks. At lower concentration addition of a carrier protein (0.1% HSA or BSA) is suggested. Please prevent freeze-thaw cycles.
Purity:
Purity of recombinant human leptin is greater than 95.0% as determined by:
(a) Gel filtration analysis of the recombinant protein.
(b) Analysis by reducing and non-reducing SDS-PAGE gel.
(a) Gel filtration analysis of the recombinant protein.
(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 human leptin was determined and was found to be Ala-Val-Pro-Ile-Gln
Dimers and Aggregates:
The purified recombinant human leptin (16K) consists of > 93% monomers as determined by gel-filtration chromatography.
Biological Activity:
PLR’s recombinant human 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 human leptin is less than 0.1 ng/µg (IEU/µg).
Protein content:
Protein quantitation in recombinant human leptin was carried out by UV spectroscopy at 280 nm using the absorbency value of 0.87 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:
Recombinant human leptin is offered by PLR for laboratory research