Leptin N82K mutant, pegylated

Mono-pegylated (with 20 kDa PEG) recombinant human leptin N82K mutant is an one polypeptide chain containing 146 amino, an additional Ala at N-terminus and one molecule of PEG 20 kDa at its N-terminus, having an expected molecular mass of ~ 35.6 kDa as determined by MS. However due to enlarged hydrodymanic volume recombinant human pegylated leptin runs on the SDS-PAGE as 48 kDa protein and in gel-filtration on Superdex 200 as over 200 kDa protein. Recombinant human pegylated leptin N82K mutant's half-life in circulation after SC injection was over 20 hours. Recombinant human leptin N82K mutant was purified by proprietary chromatographic techniques according to Salomon et al (2006) Protein Expression and Purification 47, 128–136 and then pegylated.