Leptin Human E. coli Tagless

Introduction to the Molecule

Leptin, the product of the ob (obese) gene, is a single-chain 16 kDa proteohormone consisting of 146 amino acid residues. Leptin is produced by differentiated adiocytes, although production have been demonstrated in other tissues, such as fundus of the stomach, the sceletal muscle, the liver, and the placenta. Leptin is considered to play an important role in appetite control, fat metabolism and body weight regulation. It targets the central nervous system, in particular the hypothalamus, suppressing food intake and stimulating energy expenditure. In humans, leptin levels correlate with body mass index (BMI) and percentage body fat, and are elevated even in obese individuals. Leptin has a dual action; it decreases the appetite and increases energy consumption, causing more fat to be burned.

Research topic

Energy metabolism and body weight regulation, Reproduction

Description

Total 147 AA. MW: 16 kDa (calculated).

Amino Acid Sequence

Source

E. coli

Purity

>95%

SDS-PAGE gel

12% SDS-PAGE separation of Human Leptin 1. M.W. marker – 14, 21, 31, 45, 66, 97 kDa 2. reduced and heated sample, 7μg/lane 3. non-reduced and non-heated sample, 7μg/lane

Biological Activity

Biological Activity is evidenced by inducing proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor.

Endotoxin

< 1.0 EU/ug

Formulation

Filtered (0.4 μm) and lyophilized from 0.5 mg/ml in 5mM NaHCO₃, pH= 7,4

Reconstitution

Add deionized water to prepare a working stock solution of approximately 0.5 mg/mL and let the lyophilized pellet dissolve completely. Product is not sterile! Please filter the product by an appropriate sterile filter before using it in the cell culture.

Storage, Stability/Shelf Life

Store lyophilized protein at –20°C. Lyophilized protein remains stable until the expiry date when stored at –20°C. Aliquot reconstituted protein to avoid repeated freezing/thawing cycles and store at –80°C for long term storage. Reconstituted protein can be stored at 4°C for a week.

Quality Control Test

BCA to determine quantity of the protein.

SDS PAGE to determine purity of the protein.

LAL to determine quantity of endotoxin.

Applications

ELISA, Western blotting

Note

This product is intended for research use only.

References to this Product

• Johnstone AM, Murison SD, Duncan JS, Rance KA, Speakman, JR. Factors influencing variation in basal metabolic rate include fat-free mass, fat mass, age, and circulating thyroxine but not sex, circulating leptin, or triiodothyronine. Am J Clin Nutr . Nov;82(5):941-8 (2005)
• Lee MJ, Fried SK. Multilevel regulation of leptin storage, turnover, and secretion by feeding and insulin in rat adipose tissue. J Lipid Res . Sep;47(9):1984-93 (2006)
• Matarese G, Carrieri PB, La Cava A, Perna F, Sanna V, De Rosa V, Aufiero D, Fontana S, Zappacosta S. Leptin increase in multiple sclerosis associates with reduced number of CD4(+)CD25+ regulatory T cells. Proc Natl Acad Sci U S A . Apr 5;102(14):5150-5 (2005)
• Nonaka S, Hashizume T, Yamashita T. Effects of leptin and leptin peptide amide on the release of luteinizing hormone, growth hormone and prolactin from cultured porcine anterior pituitary cells. Animal Science Journal . 77, 44-52 (2006)
• Stejskal D, Karpisek M. Adipocyte fatty acid binding protein in a Caucasian population: a new marker of metabolic syndrome?. Eur J Clin Invest . Sep;36(9):621-5 (2006)

References

• Considine R.V., Sinha M.K., Heiman M.L. et al. Serum immunoreactive leptin concentrations in normal-weight and obese humans. N. Engl. J. Med. 334, 292-295 (1996) .
• Considine R.V., Sinha M.K., Heiman M.L. et al. Serum immunoreactive leptin concentrations in normal weight and obese humans. N. Engl. J. Med. 1996; (334), 292 295.
• Halaas J.L., Gajiwala K.S., Maffei M. et al. Weight-reducing effects of the plasma protein encoded by the obese gene. Science 269, 543-546 (1995) .
• Halaas J.L., Gajiwala K.S., Maffei M. et al. Weight reducing effects of the plasma protein encoded by the obese gene. Science 1995; (269), 543 546.
• Lonnqvist F., Arner P., Nordfors L. and Shalling M. Overexpression of the obese (ob) gene in adipose tissue of human subjects. Nature Med. 1, 950-953 (1995) .
• Maffei M., Halaas J., Ravussin E. et al. Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects. Nature Med. 1, 1155-1161 (1995) .
• Maffei M., Halaas J., Ravussin E. et al. Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight reduced subjects. Nature Med. 1995; 1155 1161.
• Ricci M.R., Lee M.J., et al. Isoproterenol decreases leptin release from rat and human adipose tissue through posttranscriptional mechanisms. Am. J. Physiol. Endocrinol. Metab. 2005; (288), E798-E804.
• Zhang Y., Proenca R., Maffei M., Barone M., Leopold L., Friedman J. Positional Cloning of the Mouse Obese Gene and its Human Homologue. Nature 372, 425-432 (1994) .

By research topic:

• Energy metabolism and body weight regulation
• Reproduction

By molecule:

• Leptin