| Source: |
Escherichia coli |
| Molecular Weight: |
Approximately 16.0 kDa, a single non-glycosylated polypeptide chain containing 146 amino acids. |
| AA Sequence: |
VPIQKVQDDT KTLIKTIVTR INDISHTQSV SSKQKVTGLD FIPGLHPILT LSKMDQTLAV YQQILTSMPS RNVIQISNDL ENLRDLLHVL AFSKSCHLPW ASGLETLDSL GGVLEASGYS TEVVALSRLQ GSLQDMLWQL DLSPGC |
| Purity: |
> 97% by SDS-PAGE and HPLC analyses. |
| Biological Activity: |
Fully biologically active when compared to standard. The ED50 as determined by a chemotaxis bioassay using human Leptin R transfected BaF3 murine proB cells is less than 2 ng/mL, corresponding to a specific activity of > 5.0 × 105 IU/mg. |
| Physical Appearance: |
Sterile filtered white lyophilized (freeze-dried) powder. |
| Formulation: |
Lyophilized from a 0.2 μm filtered concentrated solution in 50 mm PB, pH 3.5, with 0.02% Tween-20. |
| Endotoxin: |
Less than 1 EU/μg of rHuLeptin as determined by LAL method. |
| Reconstitution: |
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20°C. Further dilutions should be made in appropriate buffered solutions. |
| Stability & Storage: |
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70°C as supplied.
1 month, 2 to 8°C under sterile conditions after reconstitution.
3 months, -20 to -70°C under sterile conditions after reconstitution. |
| Synonyms: |
Obese Protein, Obesity Factor |
| Background: |
Human leptin is a crucial hormone for regulating energy intake and expenditure, including appetite and metabolism. It is considered one of the most significant hormones derived from adipose tissue. The Ob (Lep) gene, responsible for coding leptin (Ob for obese, Lep for leptin), is located on human chromosome 7. This protein is predominantly produced in the adipocytes of white adipose tissue, and its levels in circulation are directly proportional to the body's total fat content.
Leptin exerts its effects primarily through receptors in the brain's hypothalamus, where it inhibits appetite by several mechanisms: (1) counteracting the effects of neuropeptide Y, a powerful feeding stimulant produced by gut and hypothalamic cells; (2) opposing the action of anandamide, another potent feeding stimulant that binds to the same receptors as THC; and (3) promoting the synthesis of α-MSH, an appetite suppressant. This inhibitory effect on appetite is long-term, contrasting with the rapid eating inhibition induced by cholecystokinin (CCK) and the slower suppression of hunger between meals mediated by PYY3-36. A deficiency in leptin or its receptor can lead to uncontrolled food intake and consequently, obesity. |
