title: Recombinant Ganoderma lucidum immunomodulatory protein modified with             polyethylene glycol.
abstract: Recombinant Ganoderma lucidum immunomodu-latory protein (rLZ-8) expressed             using the Pichia yeast eukaryotic expression system is a potential new drug for             cancer therapy; however, it has a short half-life in the body. In order to optimize             the potency and stability of rLZ-8, we modified the recombinant protein chemically             using methoxy-PEG-succinimidyl propionate (mPEG-SPA). The results indicated that             several parameters, including pH, the molar ratio of rLZ-8 to mPEG-SPA and time,             played crucial roles in the modification process. In particular, when the molar             ratio of rLZ-8 to mPEG-SPA was 1:1, rLZ-8 was modified by a single mPEG-SPA moiety.             In addition, MALDI-TOF/TOF and ESI Q-Trap results revealed that the difference             in molecular weight (MW) between the peptide-linked mPEG-SPA and the mPEG-SPA             closely matched the MW of a methionine amino acid. Taken together, these data             suggest that modification of mPEG-SPA occurred on the N-terminal helix of rLZ-8.             This modification method has laid a foundation for the development of long-acting             formulations of rLZ-8.
authors: Institute of Frontier Medical Science, Jilin University, Changchun 130021, PR China.
authors: Xiping
authors: X
authors: Zhang
authors: Fei
authors: F
authors: Sun
authors: Zhiyi
authors: Z
authors: Liu
authors: Shuqin
authors: S
authors: Zhang
authors: Chongyang
authors: C
authors: Liang
mesh_terms: D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010843:Pichia / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D020940:Reishi / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D011092:Polyethylene Glycols