Premium
The effects of sodium sulfate, glycosaminoglycans, and Congo red on the structure, stability, and amyloid formation of an immunoglobulin light‐chain protein
Author(s) -
Mclaughlin Richard W.,
De Stigter Janelle K.,
Sikkink Laura A.,
Baden Elizabeth M.,
RamirezAlvarado Marina
Publication year - 2006
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.051997606
Subject(s) - dermatan sulfate , chemistry , amyloidosis , congo red , amyloid (mycology) , glycosaminoglycan , fibril , biophysics , immunoglobulin light chain , heparin , amyloid fibril , biochemistry , chondroitin sulfate , antibody , biology , immunology , pathology , amyloid β , medicine , inorganic chemistry , disease , organic chemistry , adsorption
Light‐chain amyloidosis (AL) is characterized by immunoglobulin light‐chain fragments aggregating into amyloid fibrils that deposit extracellularly in vital organs such as the kidney, the heart, and the liver, resulting in tissue degeneration and organ failure, leading to death. Cardiac involvement is found in 50% of AL patients and presents the most severe cases with a life expectancy of less than a year after diagnosis. In this study, we have characterized the variable domain of a cardiac AL patient light chain called AL‐09. AL‐09 folds as a β‐sheet and is capable of forming amyloid fibrils both in the presence of sodium sulfate and in self‐seeded reactions under physiological conditions. Glycosaminoglycans such as dermatan sulfate and heparin promote amyloid formation of self‐seeded AL‐09 reactions, while the glycosaminoglycan chondroitin sulfate A stabilized oligomeric intermediates and did not elongate the preformed fibrils (nucleus) present in the reaction. Finally, the histological dye Congo red, known to bind to the cross β‐sheet structure of amyloid fibrils, inhibits AL‐09 amyloid fibril formation in the presence of sodium sulfate and in self‐seeded reactions. This paper provides insight into the impact of different reagents on light‐chain stability, structure, amyloid fibril formation, and inhibition.