中文摘要
　　本文的研究是以Ceph-G為基質，利用固定化酵素penicillin G acylase進行水解反應，水解產物為7-ADCA與PAA。主要可分為三部分，一是探討固定化penicillin G acylase (PGA) 酵素水解cephalosporin G的水解反應動力學；二是添加PEG對酵素水解動力學的影響；三是探討PEG與鹽類所形成的兩水相系統對cephalosporin G與其水解產物7-ADCA與PAA分配係數的影響。
　　酵素動力學主要在探討溫度、酸鹼值及添加7-ADCA與PAA對酵素反應的影響。由不同的反應溫度觀察初始速率 Vi、轉化率XA、比速率V/Vi、比速率常數ksv、失活常數kd、活化能Ea、熱失活活化能 (Ea)TD、比速率常數活化能 (Ea)sv、失活能Ed、熱力學性質 (ΔH、ΔS、與ΔG)、Km與Vm之變化。由不同的酸鹼值觀察初始速率 Vi、轉化率XA、比速率常數ksv、Km、Vm與於不同基質濃度下反應之影響。由添加7-ADCA、PAA與不同的基質濃度對酵素反應的影響，以Lineweaver-Burk圖解法求出7-ADCA、PAA與Ceph-G對酵素之抑制機制並導出penicillin G acylase水解反應速率式，以此速率式求各抑制參數 (KiA、KiP與KiS)。
　　PEG對酵素水解動力學的影響主要在探討添加不同PEG之活化能Ea、失活常數kd、失活能Ed、熱力學性質 (ΔH、ΔS、與ΔG)、不同基質濃度下之活化能Ea、Km與Vm之變化。以Lineweaver-Burk圖解法求出PEG對酵素之抑制機制並導出PEG影響penicillin G acylase水解反應之速率式，以此速率式求PEG抑制參數KiPEG。
　　兩水相系統主要在探討PEG與鹽類所形成的兩水相系統對cephalosporin G與其水解產物7-ADCA與PAA分配係數的影響。觀察改變PEG與鹽類濃度、體積比Vt / Vb、pH值、添加電解質對分配係數K、上層產率Yt、下層產率Yb、7-ADCA之分離係數 gA 與Ceph-G之分離係數 gC 的影響，尋求一最佳兩水相組成，以利酵素於兩水相進行水解反應時水解產物的初步純化。

Abstract
　In this study, cephalosporin G (Ceph-G) as the substrate was hydrolyzed by penicillin G acylase. Its hydrolyzed products are 7-aminodesacetylcephalosporanic acid (7-ADCA) and phenylacetic acid (PAA). The research work can be concluded into three parts: the kinetic study of cephalosporin hydrolysis by penicillin G acylase; the effect of adding polyethylene glycol (PEG) on the hydrolysis reaction of PGA; and the effect of aqueous two-phase system composed of different polyethylene glycols and different salts, respectively, on the partition coefficient of 7-ADCA, PAA and Ceph-G..
　The factors affecting the kinetics of PGA are temperature, pH, 7-ADCA and PAA. Variations of initial rate (Vi), conversion of 7-ADCA (XA), specific velocity (V/Vi), rate constant of specific velocity (ksv), deactivation rate constant (kd), activation energy (Ea), activation energy of thermal denature ((Ea)TD), energy of specific velocity ((Ea)sv), thermal deactivation energy (Ed), thermodynamic properties (ΔH, ΔS and ΔG) and kinetics constant (Km and Vm) obtained from different temperatures and pH were all investigated. The inhibition mechanism was estimated from a Lineweaver-Burk plot by adding different amounts of 7-ADCA and PAA. The PGA velocity model was determined taken into consideration of the inhibition mechanism of both 7-ADCA and PAA. The inhibition constants (KiA, KiP and KiS) were also calculated.
　Different concentrations of polyethylene glycols were applied to the PGA catalyzed reaction of cephalosporin G and the influence on the parameters such as activation energy (Ea), deactivation rate constant (kd), thermal deactivation energy (Ed), thermodynamic properties (ΔH, ΔS and ΔG) and kinetics constant (Km and Vm) were all discussed. The inhibition mechanism was estimated from a Lineweaver-Burk plot by adding different concentrations of polyethylene glycol. Similarly, the PGA velocity model was established from considering the inhibition mechanism of polyethylene glycol. The inhibition constants (KiPEG) were also calculated.
　The partition coefficients (K7-ADCA, KPAA and KCeph-G.) were obtained from the aqueous two-phase systems composed of different polyethylene glycols and different salts. The experimental results obtained from different concentrations of polyethylene glycols and salts, volume ratio (Vt/Vb), pH or variations of the partition coefficient by adding an electrolyte, yield in the top phase (Yt), yield in the bottom phase (Yb), 7-ADCA separation coefficient (gA) and Ceph-G separation coefficient (gC) were helpful to search for an aqueous two-phase system of optimum composition. Thus, the purification of Ceph-G hydrolyzed by PGA in an aqueous two-phase system could be successfully performed.

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