Leptin, Quadruple Antagonist, Recombinant, Human (Ob, Obese Protein, Obesity Factor)

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.\n\nRecombinant human leptin, one polypeptide chain containing 146aa and additional Ala at N-terminus and having a molecular mass of ~16kD, hLEP was mutated, resulting in the L39A/D40A/F41A/I42A mutant. \n\nAmino Acid Sequence: \nThe sequence of the first five N-terminal amino acids was determined and was found to be Ala-Val-Pro-Ile-Gln\n\nDimers and Aggregates: \nThe purified hLEP quadruple antagonist (16K) consists of > 95% monomers as determined by gel-filtration chromatography.\n\nBiological Activity: \nHuman LEP triple antagonist is capable of inhibiting leptin-induced proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor. It also inhibits various leptin effects in several in vitro bioassays.\n\nEndotoxin: \nLess than 0.1ng/ug (IEU/ug) of hLEP triple antagonist\n\nProtein Content:\nProtein quantitation was carried out by UV spectroscopy at 280nm using the absorbency value of 0.89 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).\n\nSolubility: \nIt is recommended to reconstitute the lyophilized hLEP mutant in sterile 0.4% NaHCO3 adjusted to pH 8-9, not less than 100ug/ml, which can then be further diluted to other aqueous solutions.\n\nStorage and Stability:\nLyophilized powder may be stored at 4 degrees C for short-term only. Reconstitute to nominal volume by adding sterile 0.4% NaHCO3 and store at -20 degrees C. Reconstituted product is stable for 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

L1670-15D

Size

20ug

Form

Supplied as a sterile-filtered, lyophilized powder in 0.0045mM NaHCO3.

Purity

Purified by proprietary chromatographic techniques. (same/more than) 98.0% as determined by: (a) Gel filtration analysis. (b) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.

References

1. The long-term effect of recombinant methionyl human leptin therapy on hyperandrogenism and menstrual function in female and pituitary function in male and female hypoleptinemic lipodystrophic patients. Metabolism 2005 Feb;54(2):255-63.\n2. Effect of administration of recombinant human leptin during the neonatal period on the plasma concentration and gene expression of leptin in the piglet. Biol Neonate 2005;87(1):1-7.\n3. Recombinant methionyl human leptin administration activates signal transducer and activator of transcription 3 signaling in peripheral blood mononuclear cells in vivo and regulates soluble tumor necrosis factor-alpha receptor levels in humans with relative leptin deficiency. J Clin Endocrinol Metab 2005 Mar;90(3):1625-31.\n4. Recombinant methionyl human leptin administration to achieve high physiologic or pharmacologic leptin levels does not alter circulating inflammatory marker levels in humans with leptin sufficiency or excess. J Clin Endocrinol Metab 2005 Mar;90(3):1618-24.\n5. Recombinant human leptin in women with hypothalamic amenorrhea. N Engl J Med 2004 Nov 25;351(22):2343; author reply 2343.\n6. Circulating melanin-concentrating hormone, agouti-related protein, and alpha-melanocyte-stimulating hormone levels in relation to body composition: alterations in response to food deprivation and recombinant human leptin administration. J Clin Endocrinol Metab 2005 Feb;90(2):1047-54.