Leptin qA Human, PEG

Leptin Pegylated Quadruple Antagonist Human Recombinant is a single non-glycosilated polypeptide chain containing 146 amino and an additional Ala at N-terminus acids. The Human Leptin antagonist is bound to 20 kDa mono-PEG at N-terminus, resulting in 35.6 kDa. The Human Leptin Pegylated Quadruple Antagonist was mutated, resulting in D23L/L39A/D40A/F41A that was purified by proprietary chromatographic techniques.      

Escherichia coli.

White lyophilized (freeze-dried) powder.

The Human Leptin Pegylated Quadruple Antagonist was lyophilized from a concentrated (0.65mg/ml) solution with 0.003mM NaHCO₃.

It is recommended to reconstitute the lyophilized Human Leptin Pegylated Quadruple Antagonist in sterile water or sterile 0.4% NaHCO3 adjusted to pH 8-9, not less than 100µg/ml, which can then be further diluted with other aqueous solutions.

Lyophilized Human Leptin Pegylated Quadruple Antagonist although stable at room temperature for several weeks, should be stored desiccated below -18°C. Upon reconstitution at > 0.1 and up to 2mM of Human pegylated leptin antagonist and filter sterilization Human pegylated leptin antagonist can be stored at 4°C or even room temperature for several weeks making it suitable for long term infusion studies using osmotic pumps. At lower concentration addition of a carrier protein (0.1% HSA or BSA) is suggested.

Please prevent freeze-thaw cycles.

Greater than 98.0% as determined by: 

(a) Gel filtration analysis.

(b) Analysis by SDS-PAGE. 

Human Leptin Pegylated Quadruple Antagonist inhibits leptin-induced proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor. Its in vitro activity is 6-8 fold lower than the non-pegylated human leptin antagonist but in vivo it has profound weight gain effect (as compared to the non-pegylated human leptin antagonist), resulting mainly from increased food intake. The in vivo activity of human pegylated super leptin antagonist was compared to that of human pegylated leptin antagonist is 9-27 fold higher.

Protein quantization was carried out by UV spectroscopy at 280 nm using the absorbency value of 0.88 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).

SDS

Leptin is a~16 kDa protein which is encoded by the obese gene. Leptin is a hormone which participates in regulating body weight, reproductive function and metabolism. leptin is expressed predominantly by adipocytes, which supports the idea that body weight is sensed as the total mass of fat in the body. Smaller amounts of leptin are also secreted by cellsin the epithelium of the stomach and in the placenta. Leptin receptors are highly expressed in areas of the hypothalamus which regulates body weight, as well as in T lymphocytes and vascular endothelial cells.