Poster: Late and Moved Abstracts

Abs # 972: A Proteomic Survey of Arabidopsis Copper-interacting proteins

Presenter:	Kung, Cheng-Che S., sagekung@gate.sinica.edu.tw
Authors	Kung, Cheng-Che S. (A)   Yeh, Kuo-Chen  (A)
Affiliations:	(A): Institute of BioAgricultural Sciences

Heavy metals are now some of the most serious environmental pollutants. Among them, copper is vitally essential in low concentrations, but extremely toxic at elevated concentrations. Plants have evolved a suite of mechanisms that control and respond to the uptake, accumulation and homeostasis of copper ions. Thus, copper-interacting motifs are needed to transport, chelate and sequestrate copper ions. In order to reveal the copper-interacting motifs of the plant proteome, we have intended to study the Arabidopsis copper-interacting proteins. Such proteins were isolated using immobilized metal affinity chromatography (IMAC), separated on 2-dimentional gel electrophoresis. Various affinities of Arabidopsis proteome to copper and to other divalent metal ions were compared. Thirty four proteins with affinity to copper ions were subjected to in-gel digestion with trypsin and, subsequently, the cleavage products' molecular masses were determined using MALDI-MS and/or MS/MS. The individual proteins were then identified in sequence databases using mass spectrometrically determined peptide maps. These proteins have distinct functional characterizations. They are mainly involved in redox reactions, amino acid metabolism, glutathione metabolism, translation, phosphorylation, vegetative storage proteins and TCA cycle. Certain potential copper-interacting motifs were revealed.