title: Isolation and characterization of a 60 kDa 2,4-D-binding protein from the shoot apices of peach trees (Prunus persica L.); it is a homologue of protein disulfide isomerase.
abstract: To obtain a candidate auxin-binding protein (ABP), a soluble 60 kDa protein was isolated from an extract of shoot apices of peach trees (Prunus persica L.) by affinity chromatography on a 2,4-dichlorophenoxyacetic acid (2,4-D)-linked Sepharose4B column. The 60 kDa polypeptide, designated Pp60, was purified as a single band on SDS-PAGE by column chromatography. Its dissociation constant (Kd) for [14C]-2,4-D was calculated to be 3.5 x 10(-5) M. The binding of Pp60 for [14C]-2,4-D was inhibited by naphthalene-1-acetic acid (NAA) and p-chlorophenoxyisobutyric acid (PCIB) as well as 2,4-D. Indole-3-acetic acid (IAA) had little effect on the binding. These results suggested that Pp60 is a protein that has an affinity for 2,4-D, NAA, and PCIB in vitro. The partial amino acid sequences of Pp60 showed high homology to those of protein disulfide isomerase (EC 5.3.4.1). Immunoblot analysis demonstrated that Pp60 exists ubiquitously in shoots and leaves. In fruit, expression of Pp60 is restricted at an early stage of development.
authors.affiliation: National Institute of Fruit Tree Science, Ministry of Agriculture, Forestry and Fisheries, Tsukuba, Ibaraki, Japan. ssumiko@sakura.cc.tsukuba.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Sugaya
authors.forename: A
authors.initials: A
authors.lastname: Ohmiya
authors.forename: M
authors.initials: M
authors.lastname: Kikuchi
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000378:metabolism*; D002846:Chromatography, Affinity; D007210:Indoleacetic Acids / Q000378:metabolism*; D010937:Plant Growth Regulators; D010940:Plant Proteins / Q000302:isolation & purification; D018520:Plant Shoots / Q000737:chemistry; D019704:Protein Disulfide-Isomerases / Q000302:isolation & purification*; D011956:Receptors, Cell Surface / Q000302:isolation & purification*; D019685:Rosales / Q000737:chemistry*; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C046131:auxin receptor, plant; D015084:2,4-Dichlorophenoxyacetic Acid; D019704:Protein Disulfide-Isomerases