Plant Cell-Wall Cross-Links by REDOR NMR Spectroscopy

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• 作者：Lynette Cegelski ; Robert D. O’ ; Connor ; Dirk Stueber ; Manmilan Singh ; Barbara Poliks ; Jacob Schaefer
• 刊名：Journal of the American Chemical Society
• 出版年：2010
• 出版时间：November 17, 2010
• 年：2010
• 卷：132
• 期：45
• 页码：16052-16057
• 全文大小：222K
• 年卷期：v.132,no.45(November 17, 2010)
• ISSN：1520-5126

文摘

We present a new method that integrates selective biosynthetic labeling and solid-state NMR detection to identify in situ important protein cross-links in plant cell walls. We have labeled soybean cells by growth in media containing l-[ring-d₄]tyrosine and l-[ring-4-¹³C]tyrosine, compared whole-cell and cell-wall ¹³C CPMAS spectra, and examined intact cell walls using ¹³C{²H} rotational echo double-resonance (REDOR) solid-state NMR. The proximity of ¹³C and ²H labels shows that 25% of the tyrosines in soybean cell walls are part of isodityrosine cross-links between protein chains. We also used ¹⁵N{¹³C} REDOR of intact cell walls labeled by l-[ε-¹⁵N,6-¹³C]lysine and depleted in natural-abundance ¹⁵N to establish that the side chains of lysine are not significantly involved in covalent cross-links to proteins or sugars.