摘要
The reducing and capping sites along with their local structure impact photo properties of the red bovine serum albumin-capped Au nanocluster (BSA-AuNC), however, they are hard to identify. We developped a workflow and relevant techniques using mass spectrometry (MS) to identify the reducing and capping sites of BSA-AuNCs involved in their formation and fluorescence. Digestion without disulfide cleavages yielded an Au core fraction exhibiting red fluorescence and [AunSm] ion signals and a non-core fraction exhibiting neither of them. The core fraction was identified to mainly be comprised of peptides containing cysteine residues. The fluorescence and [AunSm] signals were quenched by tris(2-carboxyethyl)phosphine, confirming that disulfide groups were required for nanocluster stabilization and fluorescence. By MS sequencing, the disulfide pairs, C75–C91/C90–C101 in domain IA, C315–C360/C359–C368 in domain IIB, and C513–C558/C557–C566 in domain IIIB, were identified to be main capping sites of red AuNCs. Peptides containing oxidized cysteines (sulfinic or cysteic acid) were identified as reducing sites mainly in the non-core fraction, suggesting that disulfide cleavages by oxidization and conformational changes contributed to the subsequent growth of nanoclusters at nearby intact disulfide pairs. This is the first report on precise identification of the reducing and capping sites of BSA-AuNCs.
| 原文 | English |
|---|---|
| 文章編號 | 1630 |
| 期刊 | Molecules |
| 卷 | 24 |
| 發行號 | 8 |
| DOIs | |
| 出版狀態 | Published - 2019 四月 25 |
指紋
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Chemistry (miscellaneous)
- Molecular Medicine
- Pharmaceutical Science
- Drug Discovery
- Physical and Theoretical Chemistry
- Organic Chemistry
引用此文
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Identifying reducing and capping sites of protein-encapsulated gold nanoclusters. / Hsu, Yu Chen; Hung, Mei Jou; Chen, Yi An; Wang, Tsu Fan; Ou, Ying Ru; Chen, Shu-Hui.
於: Molecules, 卷 24, 編號 8, 1630, 25.04.2019.研究成果: Article
TY - JOUR
T1 - Identifying reducing and capping sites of protein-encapsulated gold nanoclusters
AU - Hsu, Yu Chen
AU - Hung, Mei Jou
AU - Chen, Yi An
AU - Wang, Tsu Fan
AU - Ou, Ying Ru
AU - Chen, Shu-Hui
PY - 2019/4/25
Y1 - 2019/4/25
N2 - The reducing and capping sites along with their local structure impact photo properties of the red bovine serum albumin-capped Au nanocluster (BSA-AuNC), however, they are hard to identify. We developped a workflow and relevant techniques using mass spectrometry (MS) to identify the reducing and capping sites of BSA-AuNCs involved in their formation and fluorescence. Digestion without disulfide cleavages yielded an Au core fraction exhibiting red fluorescence and [AunSm] ion signals and a non-core fraction exhibiting neither of them. The core fraction was identified to mainly be comprised of peptides containing cysteine residues. The fluorescence and [AunSm] signals were quenched by tris(2-carboxyethyl)phosphine, confirming that disulfide groups were required for nanocluster stabilization and fluorescence. By MS sequencing, the disulfide pairs, C75–C91/C90–C101 in domain IA, C315–C360/C359–C368 in domain IIB, and C513–C558/C557–C566 in domain IIIB, were identified to be main capping sites of red AuNCs. Peptides containing oxidized cysteines (sulfinic or cysteic acid) were identified as reducing sites mainly in the non-core fraction, suggesting that disulfide cleavages by oxidization and conformational changes contributed to the subsequent growth of nanoclusters at nearby intact disulfide pairs. This is the first report on precise identification of the reducing and capping sites of BSA-AuNCs.
AB - The reducing and capping sites along with their local structure impact photo properties of the red bovine serum albumin-capped Au nanocluster (BSA-AuNC), however, they are hard to identify. We developped a workflow and relevant techniques using mass spectrometry (MS) to identify the reducing and capping sites of BSA-AuNCs involved in their formation and fluorescence. Digestion without disulfide cleavages yielded an Au core fraction exhibiting red fluorescence and [AunSm] ion signals and a non-core fraction exhibiting neither of them. The core fraction was identified to mainly be comprised of peptides containing cysteine residues. The fluorescence and [AunSm] signals were quenched by tris(2-carboxyethyl)phosphine, confirming that disulfide groups were required for nanocluster stabilization and fluorescence. By MS sequencing, the disulfide pairs, C75–C91/C90–C101 in domain IA, C315–C360/C359–C368 in domain IIB, and C513–C558/C557–C566 in domain IIIB, were identified to be main capping sites of red AuNCs. Peptides containing oxidized cysteines (sulfinic or cysteic acid) were identified as reducing sites mainly in the non-core fraction, suggesting that disulfide cleavages by oxidization and conformational changes contributed to the subsequent growth of nanoclusters at nearby intact disulfide pairs. This is the first report on precise identification of the reducing and capping sites of BSA-AuNCs.
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U2 - 10.3390/molecules24081630
DO - 10.3390/molecules24081630
M3 - Article
C2 - 31027193
AN - SCOPUS:85064805032
VL - 24
JO - Molecules
JF - Molecules
SN - 1420-3049
IS - 8
M1 - 1630
ER -