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Assaying Proteasomal Degradation in a Cell-free System in Plants
Published on: March 26, 2014
Autoproteolytic processing of aspartic proteinase from sunflower seeds
H Park1, I Kusakabe, Y Sakakibara
1Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
Abstract:
The autoproteolytic processing of mature aspartic proteinase from sunflower seeds was investigated. The mature aspartic proteinase (48 kDa) was processed at N65s-D66s in the plant-specific region of the enzyme to form 34-kDa and 14-kDa subunits. The next step was the hydrolysis of the A25s-Q26s and N97s-E98s bonds to form a 39-kDa enzyme that consisted of 29-kDa and 9-kDa disulfide-bonded subunits. Finally, bonds including V1s-M2s, M2s-S3s, C100s-D101s, and D101s-R102s were cleaved to form non-covalently bound subunits (29 kDa and 9 kDa) by eliminating the disulfide bonds in the plant-specific region of the protein.
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