asdasd14_回答_天涯问答

来自 : 天涯社区 发布时间：2021-03-24

Enzyme leakage can be reduced to minimum[186]. However, the enzyme may be
Deactivated by the chemical modification.Discrepancies in the nature of the active
Functionality,for example size,charge,and polarity might influence the nature of
The binding,for example binding position and humber of bonds formed between
The enzyme and the carriers.
Studies have revealed that the nature if inert functionalitu also has a large effect
On enzyme activity and stability.For instance,the activity of enzymeentrapped in
a gel matrix formed by a sol-gel process depends largely on the nature of the pre-
cursor,namely the side chains,suggesting the interaction of the enzyme moletion
or orientation[204].

4.3.2.2 Aquaphilicity of the carriers
Like other types of immobilized enzyme,the hydrophilicity of the matrix of the en-
Trapped enzyme has also large effect on enzyme activity,stability,and selectivity.A
Systematic study on effect of aquaphilicity is,however,still lacking,because it is
Very difficult to obtain a set of matrices with variable aquaphilicity.
Interestingly,this was beautifully demonstrated by the observation that the rations
Of the two polymers used for immobilizing enzymes such as invertase and glucose
Isomerase, and yeast cells,in PEC-HEA/PPG-HEA dictated the activity of the
Entrapped biocatalysts,suggesting that the aquaphilicity dose have great influence
On the enzyme activity[60].
In the same way as for lipase covalently immobilized on hydrophobic carriers.lipase
Entrapped in a hydrophobic matrix also displayed preference for the hydrophobic
Matrix with regard to retention of activity[77].

4.4 Effect of Entrapment
Depending on the method selected,the matrix formed also has a substantial effect
on the performance of the immobilized enzymes,for example activity,selectivity,
and stability.Thus,it is essential to select the appropriate method,according to the
peculiarities of each enzyme and application.

4.4.1 Atcivity of the Entrapped Enzyme
Retention of activitu of the immobilized enzymes is a dimensionless quantity and
Denotes usually the ratio of the specific activity fo the immobilized enzyme
(U mg-1 protein immobilized)to that of the free enzyme(U mg-1 portein).
This term is only valid when the activity of the free enzyme and the immobilized
Enzyme are measured in the same reaction and medium.When the free enzyme is
In lyophilized form or dissolved in aqueous solution.

酶泄漏可降至最低[ 186 ] 。然而，酶可
解除化学modification.Discrepancies性质的积极
功能，例如大小，费用，而且极可能影响的性质，
有约束力的，例如有约束力的地位和亨伯债券之间形成
酶和运营商。
研究表明，如果惰性的性质functionalitu也有很大影响
对酶活性和stability.For例如，在活动的enzymeentrapped
凝胶基质形成的溶胶凝胶法在很大程度上取决于的性质预先
光标，即侧链，表明酶的相互作用moletion
或方向[ 204 ] 。
4.3.2.2 Aquaphilicity运营商
像其他类型的固定化酶，亲水的矩阵恩
被困酶也很大影响酶活性，稳定性和selectivity.A
系统影响的研究aquaphilicity但是，仍然缺乏，因为它是
很难获得一套矩阵变aquaphilicity 。
有趣的是，这是美丽的观测表明，该口粮
两聚合物用于固定酶，如蔗糖，葡萄糖
异构酶和酵母细胞，在PEC-HEA/PPG-HEA决定的活动
包埋生物催化剂，这表明aquaphilicity剂量有很大影响
对酶活性[ 60 ] 。
以同样的方式为共价固定化脂肪酶的疏水carriers.lipase
包埋在疏水基还显示倾向于疏水
矩阵关于保留活动[ 77 ] 。
4.4影响圈套
根据选定的方法，形成的矩阵也有重大影响
对业绩的固定化酶，例如活性，选择性，
和stability.Thus ，必须选择适当的方法，根据
每个酶特性与应用。
4.4.1 Atcivity酶的包埋
保留activitu的固定化酶是一个无量纲的数量和
是指通常的比例的具体活动的固定化酶
（ ü毫克- 1蛋白固定化）这一自由酶（ ü毫克- 1 portein ） 。
这个词是唯一有效的活动自由酶和固定化
酶是衡量同样的反应和medium.When免费酶
在冻干形式或溶解在水溶液中。