PLANT CELL WALL CROSS LINKING VIA HYDROXYCINNAMIC ACIDS

通过羟基肉桂酸交联植物细胞壁

• 批准号: 6120991
• 负责人: JOHN RALPH
• 金额: $ 0.18万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120991
• 关键词: biological products; biomaterials; biomedical resource; enzymes; nuclear magnetic resonance spectroscopy; proteins

E. coli thioredoxin (Trx) is a general protein disulfide reductant. The Trx active site, at the N-terminus of an ?-helix, consists of Cys-Gly-Pro-Cys. The enzyme converts between dithiol and disulfide redox states. The first thiol (Cys32) has a depressed pKa relative to a typical protein thiol. This pKa can be measured by observing the titration of the C?H and C?H of Cys32 using a 2QF-COSY experiment. We have generated Trx mutants that have perturbed active site disulfide reduction potentials. pH titration of reduced mutant thioredoxins monitored by fluorescence suggest altered pKa's for Cys32. Two-dimensional 1H-NMR (2QF-CSY) of these mutants will allow accurate determination of Cys32 pKa. Physical chemistry suggests that a lower pKa will correlate with a higher (more positive) reduction potential due to stabilization of the dithiol form of Trx.

大肠杆菌硫氧还蛋白（Trx）是一种普通的二硫蛋白