title: Ovalbumin with Glycated Carboxyl Groups Shows Membrane-Damaging Activity.
abstract: The aim of the present study was to investigate whether glycated ovalbumin (OVA) showed novel activity at the lipid-water interface. Mannosylated OVA (Man-OVA) was prepared by modification of the carboxyl groups withp-aminophenyl α-dextro (d)-mannopyranoside. An increase in the number of modified carboxyl groups increased the membrane-damaging activity of Man-OVA on cell membrane-mimicking vesicles, whereas OVA did not induce membrane permeability in the tested phospholipid vesicles. The glycation of carboxyl groups caused a notable change in the gross conformation of OVA. Moreover, owing to their spatial positions, the Trp residues in Man-OVA were more exposed, unlike those in OVA. Fluorescence quenching studies suggested that the Trp residues in Man-OVA were located on the interface binds with the lipid vesicles, and their microenvironment was abundant in positively charged residues. Although OVA and Man-OVA showed a similar binding affinity for lipid vesicles, the lipid-interacting feature of Man-OVA was distinct from that of OVA. Chemical modification studies revealed that Lys and Arg residues, but not Trp residues, played a crucial role in the membrane-damaging activity of Man-OVA. Taken together, our data suggest that glycation of carboxyl groups causes changes in the structural properties and membrane-interacting features of OVA, generating OVA with membrane-perturbing activities at the lipid-water interface.
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. jenny.tang0723@gmail.com.
authors.forename: Ching-Chia
authors.initials: CC
authors.lastname: Tang
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. a786514@gmail.com.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Shi
authors.affiliation: Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 807, Taiwan. yjchen@kmu.edu.tw.
authors.forename: Ying-Jung
authors.initials: YJ
authors.lastname: Chen
authors.affiliation: Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. lschang@mail.nsysu.edu.tw.|Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan. lschang@mail.nsysu.edu.tw.
authors.forename: Long-Sen
authors.initials: LS
authors.lastname: Chang
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects*; D006031:Glycosylation; D008563:Membrane Lipids / Q000378:metabolism; D010047:Ovalbumin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D010743:Phospholipids / Q000378:metabolism; D055550:Protein Stability; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D000596:Amino Acids; D008563:Membrane Lipids; D010743:Phospholipids; D010047:Ovalbumin
keywords: carboxyl group; glycation; membrane-damaging activity; ovalbumin