Preventing serpin aggregation: The molecular mechanism of citrate action upon antitrypsin unfolding
Mary C Pearce, Craig J Morton, Susanne C Feil, Guido Hansen, Julian J Adams, Michael W Parker, Stephen P Bottomley
PROTEIN SCIENCE | WILEY | Published : 2008
The aggregation of antitrypsin into polymers is one of the causes of neonatal hepatitis, cirrhosis, and emphysema. A similar reaction resulting in disease can occur in other human serpins, and collectively they are known as the serpinopathies. One possible therapeutic strategy involves inhibiting the conformational changes involved in antitrypsin aggregation. The citrate ion has previously been shown to prevent antitrypsin aggregation and maintain the protein in an active conformation; its mechanism of action, however, is unknown. Here we demonstrate that the citrate ion prevents the initial misfolding of the native state to a polymerogenic intermediate in a concentration-dependent manner. F..View full abstract
We thank Alistair Draffan, John Lambert, and Simon Tucker from Biota Holdings Limited for advice and encouragement. We also thank Harry Tong and other BioCARS staff for their help at the Advanced Photon Source. This work was supported by the Australian Synchrotron Research Program, which is funded by the Commonwealth of Australia under the Major National Research Facilities Program. Use of the Advanced Photon Source was supported by the U. S. DOE, Basic Energy Sciences, Office of Energy Research. This work was also supported by grants from the Australian Research Council ( ARC) and the National Health and Medical Research Council (NHMRC). S. C. F. was supported by a NHMRC Industry Fellowship. M. W. P. is an ARC Federation Fellow and an NHMRC Honorary Fellow. S. P. B. is a NHMRC Senior Fellow.