Metal-assisted Assembly and Stabilization of Collagen-like Triple Helices
作者:Weibo Cai、Sen Wai Kwok、Joseph P. Taulane、Murray Goodman
DOI:10.1021/ja0442062
日期:2004.11.1
single-chain compound in 50 mM CAPS buffer (pH 10), the 1:3 Fe3+-catechol complex that formed acted as an N-terminal scaffold to assemble the triple helix. When 1 equiv of Fe3+ was added to the TRIS-assembled compound in the buffer solution, the Fe3+-catechol complex acted as an extra C-terminal scaffold, which lead to a triple helix with both termini tethered. The formation of this C-terminal complex
合成了包含儿茶酚基团的单链和 TRIS 组装的胶原模拟肽结构。当在 50 mM CAPS 缓冲液 (pH 10) 中将 1/3 当量的 Fe3+ 添加到单链化合物中时,形成的 1:3 Fe3+-儿茶酚复合物充当 N 端支架以组装三螺旋。当 1 当量的 Fe3+ 被添加到缓冲溶液中的 TRIS 组装化合物中时,Fe3+-儿茶酚复合物充当额外的 C 端支架,导致三个末端都被拴住的三螺旋。这种 C 端复合物的形成使 Tm 显着增加了 22 摄氏度!
Selective Inhibition of Fe- versus Cu/Zn-Superoxide Dismutases by 2,3-Dihydroxybenzoic Acid Derivatives.
A series of catechol derivatives were synthesised and tested for their ability to inactivate the iron-containing superoxide dismutase (Fe-SOD) from Escherichia coli and the bovine erythrocytes Cu/Zn-SOD. Incubation of catechols with Fe- or Cu/Zn SODs resulted in a time-dependent loss of enzyme activity with highly selective inhibition for the iron-dependent enzyme. Catechol-induced inactivation of SODs was correlated with the auto-oxidation of the catechol compounds to their corresponding ortho-quinone derivatives, which was found to be non-dependent on the presence of enzymes. Mass electrospray experiments on catechol-incubated Fe-SOD provided evidence for the irreversible nature of the inhibition process, yielding to a complex mixture of modified proteins.