tailieunhanh - Báo cáo khoa học: Stability and fibril formation properties of human and fish transthyretin, and of the Escherichia coli transthyretin-related protein

Human transthyretin (hTTR) is one of several proteins known to cause amyloid disease. Conformational changes in its native structure result in aggregation of the protein, leading to insoluble amyloid fibrils. The trans-thyretin (TTR)-related proteins comprise a protein family of 5-hydroxyiso-urate hydrolases with structural similarity to TTR. | ỊFEBS Journal Stability and fibril formation properties of human and fish transthyretin and of the Escherichia coli transthyretin-related protein Erik Lundberg1 Anders Olofsson2 Gunilla T. Westermark3 and A. Elisabeth Sauer-Eriksson1 1 Department of Chemistry Umea University Sweden 2 Department of MedicalBiochemistry and Biophysics Umea University Sweden 3 Division of CellBiology Diabetes Research Centre Linkoping University Sweden Keywords amyloid fibril formation HIU hydrolase transthyretin transthyretin-related protein Correspondence A. E. Sauer-Eriksson Department of Chemistry Umea University SE-90187 Umea Sweden Fax 46 90 7865944 Tel 46 90 7865923 E-mail . Received 7 November 2008 revised 20 January 2009 accepted 26 January 2009 doi Human transthyretin hTTR is one of several proteins known to cause amyloid disease. Conformational changes in its native structure result in aggregation of the protein leading to insoluble amyloid fibrils. The transthyretin TTR -related proteins comprise a protein family of 5-hydroxyiso-urate hydrolases with structural similarity to TTR. In this study we tested the amyloidogenic properties if any of sea bream TTR sbTTR and Escherichia coli transthyretin-related protein ecTRP which share 52 and 30 sequence identity respectively with hTTR. We obtained filamentous structures from all three proteins under various conditions but interestingly different structures displayed different tinctorial properties. hTTR and sbTTR formed thin curved fibrils at low pH pH 2-3 that bound thioflavin-T thioflavin-T-positive but did not stain with Congo Red CR CR-negative . Aggregates formed at the slightly higher pH of had different morphology displaying predominantly amorphous structures. CR-positive material of hTTR was found in this material in agreement with previous results. ecTRP remained soluble at pH 2-12 at ambient temperatures. By raising of the temperature fibril .