TAILIEUCHUNG - Báo cáo khoa học: High affinity copper binding by stefin B (cystatin B) and its role in the inhibition of amyloid fibrillation

We show that human stefin B, a protease inhibitor from the family of cystatins, is a copper binding protein, unlike stefin A. We have used isothermal titration calorimetry to directly monitor the binding event at pH 7 and pH 5. At pH 7 stefin B shows a picomolar affinity for copper but at pH 5 the affinity is in the nanomolar range. | ễFEBS Journal High affinity copper binding by stefin B cystatin B and its role in the inhibition of amyloid fibrillation 1 .1aAITv -T- -v2 - 3nfl -3 Eva Zerovnik Katja Skerget Magda Tusek-Znidaric Corina Loeschner Marcus W. Brazier and David R. Brown3 1 Department of Biochemistry and Molecular Biology Jozef Stefan Institute Ljubljana Slovenia 2 Department of Plant Physiology and Biotechnology NationalInstitute of Biology Ljubljana Slovenia 3 Department of Biology and Biochemistry University of Bath UK Keywords copper-binding proteins cystatin inhibition of amyloid fibril formation oligomers protein aggregation stefin B Correspondence E. Zerovnik Department of Biochemistry and Molecular Biology Jozef Stefan Institute Jamova 39 1000 Ljubljana Slovenia Fax 386 1477 3984 Tel 386 1477 3753 3900 E-mail David R. Brown Department of Biology and Biochemistry University of Bath Claverton Down Bath BA2 7AY UK Fax 44 1225 386779 Tel 44 1225 383133 E-mail bssdrb@ We show that human stefin B a protease inhibitor from the family of cystatins is a copper binding protein unlike stefin A. We have used isothermal titration calorimetry to directly monitor the binding event at pH 7 and pH 5. At pH 7 stefin B shows a picomolar affinity for copper but at pH 5 the affinity is in the nanomolar range. There is no difference in the affinity of copper between the wildtype stefin B E31 isoform and a variant Y31 isoform whereas the mutant P79S which is tetrameric does not bind copper. The conformation of stefin B remains unaltered by copper binding. It is known that below pH 5 stefin B undergoes a conformational change and amyloid fibril formation. We show that copper binding inhibits the amyloid fibril formation and to a lesser degree the initial aggregation. Similarities to and differences from other copper binding amy-loidogenic proteins are discussed. Received 3 May 2006 revised 16 July 2006 accepted 18 July 2006 doi Common .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• molecular Biology
• tumor cells
• Antimicrobial
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• bacteria
• hemoglobin
• medicine
• cell proliferation
• breast cancer
• chemical reaction
• gastric cancer
• hormone medicine
• biochemical studies
• environmental medicine