Leptin, Murine, Recombinant

Leptin inhibits food intake and stimulates energy expenditure. Leptin also has thermogenic actions and regulates enzymes of fatty acid oxidation. Severe hereditary obesity in rodents and humans is caused by defects in leptin production. In addition to its critical role in the physiologic regulation of body weight leptin has a variety of other physiologic and pathologic functions resembling those of cytokines. These functions include the regulation of hematopoiesis, angiogenesis, wound healing, inflammation, and immune responses. Recombinant Murine Leptin is a single, non-glycosylated, polypeptide chain containing 147 amino acids and having a molecular mass of 16,240 Dalton. , Sequence:, The sequence of the first five N-terminal amino acids was determined and was found to be Met-Val-Pro-Ile-Gln. Dimers and Aggregates: < 1% as determined by silver-stained SDS-PAGE gel analysis. Biological Activity: Recombinant mouse Leptin is fully biologically active when compared to standards. Biological activity of Murine Leptin is performed in two different mouse obesity models, ob/ob and NZO. Both strains of mice were treated via intraperitoneal injection once daily at a dose of 5ug Leptin/gram body weight for a period of 14 days. Significant effects on body weight, food consumption, and plasma glucose levels were observed to saline-treated controls. Protein Content: Protein quantitation was carried out by two independent methods: , 1. UV spectroscopy at 280nm using the absorbency value of 0.201 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). , 2. Analysis by RP-HPLC, using a calibrated solution of Leptin as a Reference Standard. Storage and Stability: Reconstitute to nominal volume by adding sterile dH2O and store at -20°C. Reconstituted product is stable for 12 months at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer.