Pegylated Rat Leptin Recombinant
Mono-Pegylated Leptin Rat Recombinant produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 147 amino acids and an additional Ala at N-terminus having a molecular mass of 35.6 kDa (with 20 kDa PEG) as determined by mass spectometry. However due to enlarged hydrodymanic volume it runs on the SDS-PAGE as 48 kDa protein and in gel-filtration on Superdex 200 as over 100 kDa protein. Its half-life in circulation after SC injection was over 20 hours. Rat Leptin was purified by proprietary chromatographic techniques according to Salomon et al (2006) Protein Expression and Purification 47, 128-136 and then pegylated.
Accession
Biological Activity
Pegylated Rat Leptin is capable of stimulatng proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor. Its in vitro activity is only slightly lower than the non-pegylated antagonist but in vivo it has profound weight reducing effect (as compared to the non-pegylated leptin), resulting mainly from reduced food intake.
Formulation
The protein was lyophilized from a concentrated (0.65mg/ml) solution with 0.003mM NaHCO3.
Physical Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
Greater than 99.0% as determined by:
(a) Analysis by Gel-Filtration.
(b) Analysis by SDS-PAGE.
Solubility
It is recommended to reconstitute the lyophilized pegylated Rat Leptin in sterile 0.4% NaHCO3 adjusted to pH-8.5, not less than 100ug/ml, which can then be further diluted to other aqueous solutions.
Source
Stability
Lyophilized Rat Leptin although stable at room temperature for 3 weeks, should be stored desiccated below -18oC. Upon reconstitution Rat Leptin should be stored at 4oC between 2-7 days and for future use below -18oC.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please prevent freeze-thaw cycles.
Synonyms
OB Protein, Obesity Protein, OBS, Obesity factor.
