本文關(guān)鍵詞： 仿生鈦化 自組裝 氧化鈦 精蛋白 酶載體 包埋　出處：《天津大學(xué)》2009年博士論文　論文類型：學(xué)位論文

【摘要】： 仿生礦化過程可在溫和條件下(常溫、中性pH)利用生物模板或合成模板誘導(dǎo)無機(jī)氧化物的形成,并可通過模板的自組裝來調(diào)控?zé)o機(jī)氧化物的形貌,這為酶固定化提供了新的途徑。層層自組裝過程可在常溫水溶液中進(jìn)行,條件溫和,也能維持酶分子的天然構(gòu)象和生物活性。這都將為固定化酶提供適宜的微環(huán)境。本論文主要研究仿生鈦化和自組裝及其用于固定化酶載體設(shè)計(jì)與制備。主要研究?jī)?nèi)容總結(jié)如下: 第一部分,仿生鈦化過程機(jī)理的研究。利用精蛋白誘導(dǎo)鈦的水溶性前驅(qū)體Ti-BALDH生成氧化鈦納米粒子,仿生合成的氧化鈦為無定形的球形粒子,通過進(jìn)一步高溫煅燒處理可制得不同晶形的氧化鈦。通過改變pH值、溫度等條件可調(diào)控精蛋白自組裝,進(jìn)而調(diào)控氧化鈦粒子大小。對(duì)仿生鈦化過程機(jī)理及精蛋白在誘導(dǎo)合成氧化鈦過程中的催化和模板雙重作用進(jìn)行了詳細(xì)的闡述。 第二部分,仿生鈦化直接用于固定化醇脫氫酶(YADH)的研究。選用精蛋白作為誘導(dǎo)劑,Ti-BALDH作為鈦前驅(qū)體,采用共沉淀法在精蛋白誘導(dǎo)生成氧化鈦的同時(shí)將YADH固定,并提出了共沉淀法固定化酶的機(jī)理。與游離YADH相比,固定化的YADH能保持約95%以上的初始活性,并顯示出良好的溫度、pH、重復(fù)使用和儲(chǔ)藏穩(wěn)定性。 第三部分,仿生鈦化與LbL層層自組裝相結(jié)合制備雜化微囊用于固定化YADH的研究。以CaCO3微粒為模板,在其表面交替組裝精蛋白層和氧化鈦層,然后用EDTA溶液去除模板得到protamine titania雜化微囊,闡明了微囊的形成過程和機(jī)理。將微囊用于固定化YADH的研究,發(fā)現(xiàn)YADH包埋率約為68%,微囊可為酶提供適宜的微環(huán)境,使酶保持較高的活性和重復(fù)使用穩(wěn)定性。 第四部分,仿生鈦化用于制備多酶固定化載體。提出多酶微工廠的概念,設(shè)計(jì)并制備出具有Shells-in-Shell結(jié)構(gòu)的多酶固定化載體。將protamine titania LbL層層自組裝微囊包埋到Alg-Pro-Ti微囊中,以Alg-Pro-Ti微囊作為廠房, LbL微囊作為工作車間。含不同酶種的LbL微囊組成“酶催化裝配線”,對(duì)輸入的底物分子進(jìn)行高效“加工”。Alg-Pro-Ti微囊將多酶共固定在局限空間內(nèi),縮短了多酶活性位點(diǎn)的距離,能提高反應(yīng)的發(fā)生幾率和效率,并有利于分離。 最后,仿生鈦化的拓展應(yīng)用,利用仿生法制備氧化鋯。以精蛋白和溶菌酶誘導(dǎo)仿生鋯化過程,可得到無定形的氧化鋯。詳細(xì)探討了溶菌酶在仿生鋯化過程中的催化和模板雙重作用,并對(duì)催化水解K2ZrF6的機(jī)理進(jìn)行了解釋。將仿生鋯化過程用于YADH的固定化,固定化YADH表現(xiàn)出較高的溫度和pH穩(wěn)定性。
[Abstract]:Biomimetic mineralization can induce the formation of inorganic oxides under mild conditions (normal temperature, neutral pH) by using biological or synthetic templates, and the morphology of inorganic oxides can be regulated by self-assembly of templates. This provides a new way for enzyme immobilization. The layer by layer self-assembly process can be carried out in aqueous solution at room temperature under mild conditions. It can also maintain the natural conformation and biological activity of enzyme molecules, which will provide a suitable microenvironment for immobilized enzymes. In this thesis, bionic titanium and self-assembly and their applications in the design and preparation of immobilized enzyme carriers are studied. The main research contents are summarized as follows:. In the first part, the mechanism of bionic titanization was studied. The water-soluble precursor Ti-BALDH was induced to form titanium oxide nanoparticles by protamine, and the synthesized titanium oxide was amorphous spherical particles. Titanium oxide with different crystal shapes can be prepared by further calcination at high temperature. The protamine self-assembly can be controlled by changing pH value and temperature. The mechanism of bionic titaniation and the catalytic and templating roles of protamine in the induced synthesis of titanium oxide were discussed in detail. In the second part, the study of immobilized alcohol dehydrogenase (YADH) with bionic titanium was studied. The protamine was used as the inducer of Ti-BALDH as the precursor of titanium, and the YADH was immobilized by co-precipitation method while the protamine induced the formation of titanium oxide. The mechanism of immobilization of enzyme by coprecipitation method was put forward. Compared with free YADH, the immobilized YADH could maintain the initial activity of more than 95%, and showed good temperature pH, reuse and storage stability. In the third part, hybrid microcapsules were prepared by combining bionic titanium with LbL layer by layer self-assembly. Using CaCO3 particles as template, protamine layer and titanium oxide layer were alternately assembled on the surface. Then the protamine titania hybrid microcapsules were obtained by removing the template with EDTA solution, and the formation process and mechanism of the microcapsules were elucidated. When the microcapsules were used in the study of immobilized YADH, it was found that the embedding rate of YADH was about 68%, and the microcapsules could provide suitable microenvironment for the enzyme. The enzyme maintained high activity and reused stability. In 4th, bionic titanium was used to prepare multi-enzyme immobilized carrier. The concept of multi-enzyme microfactory was put forward, and the multi-enzyme immobilized carrier with Shells-in-Shell structure was designed and prepared. The protamine titania LbL was embedded in the Alg-Pro-Ti microcapsule layer by layer. Alg-Pro-Ti microcapsules were used as workshop and LbL microcapsules as workshop. LbL microcapsules containing different enzyme species constituted "enzyme catalytic assembly line". The imported substrate molecules were efficiently "processed". Alg-Pro-Ti microcapsules were co-immobilized in limited space. It can shorten the distance of multi-enzyme activity sites, improve the probability and efficiency of reaction, and is beneficial to separation. Finally, the application of bionic titanization is extended, and zirconia is prepared by bionic method. The process of bionic zirconization is induced by protamine and lysozyme. Amorphous zirconia can be obtained. The catalytic and template roles of lysozyme in bionic zirconization are discussed in detail, and the mechanism of catalytic hydrolysis of K2ZrF6 is explained. The bionic zirconization process is used for immobilization of YADH. The immobilized YADH exhibited high temperature and pH stability.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2009
【分類號(hào)】：R341;TQ11

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 王翠;制備納米氧化硅粒子固定化酶[D];河北工業(yè)大學(xué);2011年

2 孫倩蕓;仿生硅化與自組裝固定化酶用于二氧化碳轉(zhuǎn)化的研究[D];天津大學(xué);2009年

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本文編號(hào)：1531019