KINETICS OF INTERACTION BETWEEN CERULOPLASMIN AND REDUCING SUBSTRATES
KINETICS OF INTERACTION BETWEEN CERULOPLASMIN AND REDUCING SUBSTRATES
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DOI：
10.1111/j.1432-1033.1973.tb02954.x
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发表时间：
1973-01-01
期刊：
影响因子：
--
通讯作者：
PETTERSS.G
中科院分区：
文献类型：
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作者：
GUNNARSS.PO;NYLEN, U;PETTERSS.G
抗坏血酸对铜蓝蛋白 610 nm 发色团的脱色是由于酶和底物之间的速率决定二阶相互作用。该过程的表观速率常数似乎与蛋白质 340 nm 发色团的氧化态无关，并且在 pH 5-7 范围内随 pH 值而降低。各种底物还原铜蓝蛋白的二阶速率常数与相应 Km 值的倒数线性相关，并且在大小上与稳态动商 V/Km 一致。这意味着各种底物氧化速率的差异主要归因于 610 nm 发色团还原速率的差异，并与还原底物电离电位的差异相关。
Decolourization of the 610‐nm chromophore of ceruloplasmin by ascorbate is due to a ratedetermining second‐order interaction between enzyme and substrate. Apparent rate constants for this process appear to be independent of the oxidation state of the 340‐nm chromophore of the protein, and decrease with pH over the range pH 5–7.Second‐order rate constants for the reduction of ceruloplasmin by various substrates are linearly correlated to the reciprocal value of the correspondingKm‐values, and agree in magnitude with the steady‐state kinetic quotientV/Km. This means that differences in the rate of oxidation of various substrates can be mainly attributed to differences in the rate of reduction of the 610‐nm chromophore and correlated to differences in the ionization potential of the reducing substrates.