title: Arg 901 in the AE1 C-terminal tail is involved in conformational change but not in substrate binding.
abstract: In our previous paper, we demonstrated that Arg 901 in the C-terminal tail of human AE1 (band 3, anion exchanger 1) had a functional role in conformational change during anion exchange. To further examine how Arg 901 is involved in conformational change, we expressed various Arg 901 mutants and alanine mutants of the C-terminal tail (from Leu 886 to Val 911) on the plasma membrane of Saccharomyces cerevisiae and evaluated the kinetic parameters of sulfate ion transport. As a result, Vmax decreased as the hydrophobicities of the 901st and peripheral hydrophilic residues increased, indicating that the hydrophobicity of the C-terminal residue is involved in the conformational change. We also found the alkali and protease resistance of the C-terminal region after Arg 901 modification with hydroxyphenylglyoxal (HPG) or phenylglyoxal (PG), a hydrophobic reagent. These results suggested that the increased hydrophobicity of the C-terminal region around Arg 901 leads to inefficient conformational change by the newly produced hydrophobic interaction.
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Takazaki
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Abe
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Mikako
authors.initials: M
authors.lastname: Yagi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ueda
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
authors.forename: Naotaka
authors.initials: N
authors.lastname: Hamasaki
mesh_terms: D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001120:Arginine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D017136:Ion Transport / Q000502:physiology; D007700:Kinetics; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D011994:Recombinant Proteins; D001120:Arginine