title: Lysine-deficient lymphotoxin-α mutant for site-specific PEGylation.
abstract: The cytokine lymphotoxin-α (LTα) is a promising anticancer agent; however, its instability currently limits its therapeutic potential. Modification of proteins with polyethylene glycol (PEGylation) can improve their in vivo stability, but PEGylation occurs randomly at lysine residues and the N-terminus. Therefore, PEGylated proteins are generally heterogeneous and have lower bioactivity than their non-PEGylated counterparts. Previously, we created phage libraries expressing mutant LTαs in which the lysine residues of wild-type LTα (wtLTα) were substituted for other amino acids. Here, we attempted to create a lysine-deficient mutant LTα with about the same bioactivity as wtLTα by using these libraries and site-specific PEGylation of the N-terminus. We isolated a lysine-deficient mutant LTα, LT-K0, with almost identical bioactivity to that of wtLTα against mouse LM cells. The bioactivity of wtLTα decreased to 10% following random PEGylation, whereas that of LT-K0 decreased to 50% following site-specific PEGylation; PEGylated LT-K0 retained five times the bioactivity of randomly PEGylated wtLTα. These results suggest that site-specific PEGylated LT-K0 may be useful in cancer therapy.
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Narimatsu
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Hikaru
authors.initials: H
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Masano
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Morishige
authors.forename: Xinglei
authors.initials: X
authors.lastname: Yao
authors.forename: Aya
authors.initials: A
authors.lastname: Tanabe
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mukai
authors.forename: Naoki
authors.initials: N
authors.lastname: Okada
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Nakagawa
mesh_terms: D000818:Animals; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D008233:Lymphotoxin-alpha / Q000235:genetics* / Q000378:metabolism; D008239:Lysine / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D011092:Polyethylene Glycols / Q000378:metabolism*
chemical_list: D008233:Lymphotoxin-alpha; D011092:Polyethylene Glycols; D008239:Lysine