tailieunhanh - Báo cáo khoa học: Dissociation/association properties of a dodecameric cyclomaltodextrinase Effects of pH and salt concentration on the oligomeric state

As an effort to elucidate the quaternary structure of cyclomaltodextrinase I-5 (CDase I-5) as a function of pH and salt concentration, the dissoci-ation/association processes of the enzyme were investigated under various pH and salt conditions. Previous crystallographic analysis of CDase I-5 indicated that it existed exclusively as a dodecamer at pH , forming an assembly of six 3D domain-swapped dimeric subunits. | ềFEBS Journal Dissociation association properties of a dodecameric cyclomaltodextrinase Effects of pH and salt concentration on the oligomeric state Hee-Seob Lee1 Jin-Soo Kim1 Kyuho Shim1 Jung-Woo Kim1 Kuniyo Inouye2 Hiroshi Oneda2 ft Young-Wan Kim1 Kyung-Ah Cheong1 Hyunju Cha1 Eui-Jeon Woo3 Joong Hyuck Auh1 Sung-Joon Lee4 Jung-Wan Kim5 and Kwan-Hwa Park1 1 Center for AgriculturalBiomaterials and Schoolof AgriculturalBiotechnology SeoulNationalUniversity Seoul Korea 2 Division of Food Science and Biotechnology Graduate Schoolof Agriculture Kyoto University Sakyo-ku Kyoto Japan 3 Systemic Proteomics Research Center Korea Research Institute of Bioscience and Biotechnology Taejon Korea 4 Division of Food Science College of Life and EnvironmentalSciences Korea University Seoul Korea 5 Department of Biology University of Incheon Incheon Korea Keywords cyclomaltodextrinase dissociation association dodecamer oligomerization quaternary structure maltogenic amylase Correspondence . Park Center for Agricultural Biomaterials and School of Agricultural Biotechnology Seoul National University Seoul 151-921 Korea Fax 82 28735095 Tel 82 28804852 E-mail parkkh@ Enzymes cyclomaltodextrinase EC . Received 29 August 2005 revised 28 October 2005 accepted 2 November 2005 doi As an effort to elucidate the quaternary structure of cyclomaltodextrinase I-5 CDase I-5 as a function of pH and salt concentration the dissoci-ation association processes of the enzyme were investigated under various pH and salt conditions. Previous crystallographic analysis of CDase I-5 indicated that it existed exclusively as a dodecamer at pH forming an assembly of six 3D domain-swapped dimeric subunits. In the present study analytical ultracentrifugation analysis suggested that CDase I-5 was present as a dimer in the pH range of while the dodecameric form was predominant at pH values above . No dissociation of the dodecamer was .