含义Meaning
把米氏方程取倒数线性化:纵截距 \(1/V_{\max}\),横截距 \(-1/K_\mathrm{M}\),斜率 \(K_\mathrm{M}/V_{\max}\)。
The reciprocal of the Michaelis–Menten equation is linear: y-intercept \(1/V_{\max}\), x-intercept \(-1/K_\mathrm{M}\), slope \(K_\mathrm{M}/V_{\max}\).
符号说明Symbols
| 符号Symbol | 含义 Meaning | 单位 Unit |
|---|---|---|
| \(1/v_0\) | 初速率倒数reciprocal initial rate | L·s·mol⁻¹ |
| \(1/[\mathrm{S}]\) | 底物浓度倒数reciprocal substrate concentration | L·mol⁻¹ |
推导Derivation
对米氏方程两边取倒数:\(\frac{1}{v_0} = \frac{K_\mathrm{M} + [\mathrm{S}]}{V_{\max}[\mathrm{S}]}\)。
Invert the Michaelis–Menten equation.
拆成两项即为 \(y = mx + b\) 形式,\(x = 1/[\mathrm{S}]\),\(y = 1/v_0\)。
Split into two terms: a straight line in \(x = 1/[\mathrm{S}]\), \(y = 1/v_0\).
令 \(y = 0\) 得横截距 \(-1/K_\mathrm{M}\)。
Setting \(y = 0\) gives the x-intercept \(-1/K_\mathrm{M}\).
适用条件与局限Assumptions & limitations
倒数变换放大低底物浓度点(速率小、误差大)的权重,参数估计偏差大;现代分析宜对原始数据做非线性拟合。
Inversion over-weights low-[S] points with large relative errors; fit the hyperbola directly by non-linear regression.
主要用途是直观判断抑制类型(直线交点位置)。
Its main value is diagnosing inhibition type from where lines cross.