Figure 1

Substrate inhibition. Reaction for substrate inhibition was according to the Eq. (1). a Substrate saturation curves. Lines were drawn in accordance with Eq. (2). The following values of kinetic parameters were used for calculation. Rate constant, V _max  = 1; K _m  = 1. Curve 1 complete substrate inhibition; k = 1, k′ = 0, K _m  = 1, \(K_{{_{i} }}^{\prime } = 5\), K _i  = ∞. Curve 2 partial substrate inhibition; k = 1, k′ = 0.2, K _m  = 1, \(K_{{_{i} }}^{\prime } = 5\), K _i  = ∞. Curve 3 partial substrate inhibition; k = 1, k′ = 0.2, K _m  = 1, \(K_{{_{i} }}^{\prime } = 10\), K _i  = 5. Curve 4 partial substrate inhibition; k = 1, k′ = 0.2, K _m  = 1, \(K_{{_{i} }}^{\prime } = 10\). Curve 5 no substrate inhibition; k = 1, k′ = 0, K _m  = 1, \(K_{{_{i} }}^{\prime } = \infty\), K _i  = ∞. b Quotient velocity plot. (V _max  − v)/v was plotted against the substrate concentrations. c Reciprocal of the quotient velocity plot. Dotted lines were theoretical curves, and solid linear lines were drawn within higher substrate concentration range.