Interaction between beta-amyloid and lens alphaB-crystallin.
In Alzheimer's disease, beta-amyloid peptides (betaA(1-40) and betaA(1-42)) are deposited on the brain cell surfaces as neurotoxic plaques. Some reports indicate that small heat shock proteins, Hsp27 and alphaB-crystallin, colocalize in the plaques, but their functions are not known. Interaction between betaA and alphaB-crystallin must be determined in order to understand the role of alphaB-crystallin in betaA fibril formation. We used a pyrene (Pyr)-labeled betaA(1-40) in a fluorescence energy transfer experiment. Upon incubation together at 37 degrees C, energy transfer between Trp of alphaB-crystallin and Pyr of Pyr-labeled betaA was observed, indicating that betaA participated in subunit exchange of alphaB-crystallin, which promoted fibril formation.
Liang
J J
JJ
Center for Ophthalmic Research, Brigham and Women's Hospital, Department of Ophthalmology, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA. jliang@rics.bwh.harvard.edu
D000544:Alzheimer Disease / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D052160:Benzothiazoles; D002942:Circular Dichroism; D003459:Crystallins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D011994:Recombinant Proteins; D013050:Spectrometry, Fluorescence; D013844:Thiazoles / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism; D014466:Ultraviolet Rays
D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D003459:Crystallins; D011994:Recombinant Proteins; D013844:Thiazoles; C009462:thioflavin T; D014364:Tryptophan