Processing of amyloid beta-peptides by neutral cysteine protease bleomycin hydrolase.
We studied the processing of amyloid beta-peptides (Abetas) including Abeta(1-40), Abeta(1-42) and pAbeta(3-42) by rat neutral cysteine protease bleomycin hydrolase (BH) according to the methods of SDS-PAGE, HPLC and matrix-assisted laser desorption/inonization time-of-flight mass spectrometry (MALDI-TOF MS). BH significantly processed them by novel features of its diverse activities. It initially cleaved at two sites, His(14)-Gln(15) and Phe(19)-Phe(20) degraded to short intermediates then to amino acids by aminopeptidase and/or carboxypeptidase activities. Also, full-length Abetas were clipped at the carboxyl(C)-terminal region. On the other hand, BH cleaved at only the His(14)-Gln(15) bond in pbetaA(3-42) within a short period of the reaction by endopeptidase activity, and processed the intermediates in order by carboxypeptidase activity. On processing by BH, it found that both fibrillar Abeta(1-40) and Abeta(1-42) were more resistant than non-fibrillar peptides. These results indicate that the processing specificity of BH depends upon the structure and sequence of Abetas.
Laboratory of Biochemistry, Faculty of Arts and Sciences, Sagami Women's University, 2-1-1 Bunkyo, Sagamihara-shi, Kanagawa 228-8533, Japan.
Akane
A
Kajiya
Hiroyuki
H
Kaji
Toshiaki
T
Isobe
Atsushi
A
Takeda
D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D003546:Cysteine Endopeptidases; C031262:bleomycin hydrolase