WO2022151828A1 - 膜状固定化细胞、多肽、寡肽或蛋白质及其制备方法 - Google Patents

膜状固定化细胞、多肽、寡肽或蛋白质及其制备方法 Download PDF

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WO2022151828A1
WO2022151828A1 PCT/CN2021/130403 CN2021130403W WO2022151828A1 WO 2022151828 A1 WO2022151828 A1 WO 2022151828A1 CN 2021130403 W CN2021130403 W CN 2021130403W WO 2022151828 A1 WO2022151828 A1 WO 2022151828A1
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chitosan
membrane
cells
oligopeptides
polypeptides
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PCT/CN2021/130403
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French (fr)
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张仲康
王骏
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百瑞全球有限公司
张仲康
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Priority to US18/272,347 priority Critical patent/US20230392136A1/en
Priority to EP21919019.6A priority patent/EP4279589A1/en
Publication of WO2022151828A1 publication Critical patent/WO2022151828A1/zh

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    • C12N11/00Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
    • C12N11/02Enzymes or microbial cells immobilised on or in an organic carrier
    • C12N11/10Enzymes or microbial cells immobilised on or in an organic carrier the carrier being a carbohydrate
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    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K17/00Carrier-bound or immobilised peptides; Preparation thereof
    • C07K17/02Peptides being immobilised on, or in, an organic carrier
    • C07K17/10Peptides being immobilised on, or in, an organic carrier the carrier being a carbohydrate
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    • C12N1/00Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
    • C12N1/20Bacteria; Culture media therefor
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    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/90Isomerases (5.)
    • C12N9/92Glucose isomerase (5.3.1.5; 5.3.1.9; 5.3.1.18)
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    • C12Y503/00Intramolecular oxidoreductases (5.3)
    • C12Y503/01Intramolecular oxidoreductases (5.3) interconverting aldoses and ketoses (5.3.1)
    • C12Y503/01018Glucose isomerase (5.3.1.18)
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    • C12N2533/00Supports or coatings for cell culture, characterised by material
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    • C12N2537/10Cross-linking

Definitions

  • the present invention belongs to the field of immobilized cells and immobilized proteins, and in particular, relates to membrane-like immobilized cells, polypeptides, oligopeptides or proteins and preparation methods thereof.
  • enzyme immobilization methods are numerous, such as physical adsorption, affinity linkage, covalent cross-linking, flocculation, etc. (see the document "Roger A. Sheldon, 2007, Advanced Synthesis & Catalysis, 349: 1289-1307”).
  • the manufacturing process of the existing carrier is complicated, for example: the preparation of silicon carrier requires the use of a variety of organic solutions (Yuan Zhongyi, Wu Xingjia, Li Shiyun, Ji Xinsong, "Preparation of a beaded chitosan carrier and its application in enzymes].
  • the method of immobilization Chinese Patent Application Publication No.: CN1407103A
  • the preparation of porous composite oxides requires the use of high temperature and high pressure (Quan Haozhen, Hong Shunjiao, Bai Guidong, Jin Huizhen, Pu Dongkun, "Porous Composite Oxide Manufacturing Method", Chinese Patent Application Publication No.: CN1171295A).
  • the general gel carrier production process is simple, just drop the gel solution with a syringe into a solution that can make it gelled to form gel particles. For example: drop sodium alginate into calcium chloride solution, drop carrageenan into potassium chloride solution.
  • this technology needs to design specific equipment for production in industrial production (Zeng Zhaojing, Ouyang Pingkai, Pan Guangliang, "Immobilized Cell Carrier Forming Machine", Chinese Patent Application Publication No.: CN2181511Y), which greatly increases the production cost. Therefore, immobilization methods with simple preparation and low production cost have been the goal of researchers in the field.
  • the present invention provides membrane-like immobilized cells, polypeptides, oligopeptides or proteins and preparation methods thereof.
  • the present invention provides:
  • a method for preparing membrane-like immobilized cells, polypeptides, oligopeptides or proteins comprising the following steps:
  • step 1) uses chitosan without pre-crosslinking
  • the method further includes:
  • step 5) Mix the membrane-like immobilized cells, polypeptides, oligopeptides or proteins obtained in step 4) with phosphate to cross-link the chitosan molecules therein.
  • phosphate is selected from one or more of polyphosphates, polymetaphosphates and pyrophosphates.
  • step 3 The method according to (1), wherein the crosslinking agent in step 3) includes a polyaldehyde compound and genipin.
  • step 2 comprises,
  • step 2 The method according to (1), wherein in step 2), the weight ratio of the unfilmed chitosan to the cells is 1:(1-20).
  • step 2) The method according to (1), wherein in step 2), the weight ratio of the unfilmed chitosan to the polypeptide, oligopeptide or protein is (0.5-10):1.
  • step 3 The method according to (1), wherein in step 3), the weight ratio of the crosslinking agent to the unfilmed chitosan in the mixed solution is (0.005-10):1.
  • a membrane-like immobilized cell, polypeptide, oligopeptide or protein prepared according to the method of any one of (1) to (11).
  • the present invention has the following advantages and positive effects:
  • the present invention innovatively proposes to adopt a one-step method to prepare membrane immobilized cells, polypeptides, oligopeptides or proteins.
  • One-step method means that the preparation of the membrane-like chitosan carrier and the immobilization of cells, polypeptides, oligopeptides or proteins are completed at the same time, which reduces the cost and time of preparing the carrier, the preparation process is simple, no specific equipment is required, and the operation, suitable for industrial production.
  • the loading of cells, polypeptides, oligopeptides, proteins or enzymes can be flexibly controlled by the amount of carrier material.
  • the main component of the carrier used in the present invention is chitosan, which is a natural non-toxic high-molecular polymer and does not cause pollution to the environment.
  • the invention adopts phosphate to cross-link chitosan, which can effectively reduce the swelling degree of membrane-like immobilized cells, polypeptides, oligopeptides, proteins or enzymes in contact with water.
  • phosphate is a harmless food additive, safe and reliable.
  • FIG. 1 shows a photograph of Sample 1 in Experimental Example 1 before being soaked in deionized water.
  • FIG. 2 shows a photograph of Sample 1 in Experimental Example 1 after soaking in deionized water.
  • FIG. 3 shows a photograph of Sample 2 in Experimental Example 1 before being soaked in deionized water.
  • FIG. 4 shows a photograph of Sample 2 in Experimental Example 1 after being soaked in deionized water.
  • FIG. 5 shows a photograph of Sample 3 in Experimental Example 1 before being soaked in deionized water.
  • FIG. 6 shows a photograph of Sample 3 in Experimental Example 1 after soaking in deionized water.
  • FIG. 7 shows a photograph of Sample 4 in Experimental Example 1 before being soaked in deionized water.
  • FIG. 8 shows a photograph of Sample 4 in Experimental Example 1 after being soaked in deionized water.
  • FIG. 9 shows a photograph of Sample 5 in Experimental Example 1 before being soaked in deionized water.
  • FIG. 10 shows a photograph of Sample 5 in Experimental Example 1 after soaking in deionized water.
  • the present invention provides a method for preparing membrane-like immobilized cells, polypeptides, oligopeptides or proteins, comprising the following steps:
  • step 1) uses chitosan without pre-crosslinking
  • the method further includes:
  • step 5) Mix the membrane-like immobilized cells, polypeptides, oligopeptides or proteins obtained in step 4) with phosphate to cross-link the chitosan molecules therein.
  • the present invention utilizes the film-forming property of chitosan to prepare film-like immobilized cells, polypeptides, oligopeptides or proteins, wherein the carrier is film-like chitosan, that is, chitosan film.
  • a membrane-like immobilized cell, polypeptide, oligopeptide or protein is an immobilized cell, polypeptide, oligopeptide or protein membrane, and the two terms are used interchangeably.
  • the method for preparing immobilized cells or enzymes is to prepare a carrier first, and then chemically or physically immobilize the cells or enzymes on the carrier.
  • the above method of the present invention breaks the inherent thinking, enables the preparation of the membrane-like chitosan carrier and the immobilization of cells, polypeptides, oligopeptides or proteins to be completed at the same time, and realizes one step of the process (carrier preparation and immobilization) that usually needs to be completed in two steps.
  • the method is completed, reducing the cost and time of preparing the carrier.
  • the cross-linked film-forming material helps to reduce the degree of swelling, and the commonly used cross-linking agent (eg epichlorohydrin) has certain toxicity, so the convenience of industrial application is greatly limited.
  • the use of phosphate in the present invention not only solves the problem of water swelling after film formation, but also is an environmentally friendly material.
  • chitosan as used herein is known in the art and is an aminopolysaccharide that is not water soluble but can be dissolved by acetic acid.
  • non-film-formed chitosan means that the chitosan is not film-like, that is, the chitosan is not in the state of a film-like carrier required for immobilizing cells, polypeptides, oligopeptides or proteins.
  • the unfilmed chitosan can be, for example, chitosan powder or chitosan solution. Neither chitosan powder nor chitosan solution is a carrier for immobilizing cells, polypeptides, oligopeptides or proteins.
  • non-pre-crosslinked chitosan refers to chitosan in its natural state that has not been treated with a crosslinking agent.
  • pre-crosslinked chitosan means that chitosan is treated with phosphate to cause intermolecular crosslinking between the chitosan molecules.
  • the deacetylation degree of the used chitosan is 80% or more.
  • co-cross-linking refers to the cross-linking effect between chitosan and cells, polypeptides, oligopeptides or proteins, so that cells, polypeptides, oligopeptides or proteins are combined with chitosan through covalent bonds, thereby Cells, polypeptides, oligopeptides or proteins are immobilized on chitosan.
  • the present invention adopts a one-step method for carrier preparation and immobilization, the loss of cell, protein or enzyme activity in the carrier preparation process needs to be considered.
  • the present invention preferably cross-links chitosan with phosphate in advance, and then uses the pre-cross-linked chitosan to prepare membrane-like immobilized cells, proteins or enzymes.
  • Pre-crosslinked chitosan can be provided by intermolecular cross-linking of chitosan by reacting chitosan without pre-crosslinking with phosphate.
  • the pre-cross-linked chitosan can be prepared by mixing phosphate with unpre-cross-linked chitosan at room temperature for a suitable time (eg, 30 minutes).
  • the phosphate is selected from one or more of polyphosphates, polymetaphosphates and pyrophosphates.
  • the polyphosphate is preferably sodium tripolyphosphate.
  • the polymetaphosphate is preferably sodium trimetaphosphate and sodium hexametaphosphate.
  • the pyrophosphate is preferably sodium pyrophosphate.
  • the cross-linking agent in step 3) is a polyaldehyde compound and genipin.
  • the polyaldehyde compounds include glutaraldehyde and dialdehyde starch.
  • the unfilmed chitosan is chitosan powder, and step 2) comprises,
  • the final concentration of acetic acid is 0.5%-10% (v/v).
  • the weight ratio of the unfilmed chitosan to the cells is preferably 1:(1-20); the weight of the unfilmed chitosan to the polypeptide, oligopeptide or protein The ratio is preferably (0.5-10):1.
  • step 3 the weight ratio of the crosslinking agent to the unfilmed chitosan in the mixed solution is preferably (0.005-10):1.
  • Step 3) can be carried out at room temperature for a suitable time (eg 10 minutes).
  • the weight ratio of the phosphate to the unpre-crosslinked chitosan is preferably (0.1-20):1.
  • the weight ratio of phosphate to unpre-crosslinked chitosan is preferably (0.1-20):1.
  • the method of the present invention comprises the following steps in sequence:
  • the method of the present invention comprises the following steps in sequence:
  • the protein includes an enzyme.
  • the present invention also provides membrane-like immobilized cells, polypeptides, oligopeptides or proteins prepared by the method of the present invention, ie immobilized cell, polypeptide, oligopeptide or protein membranes.
  • Example 1 Preparation of immobilized E. coli cell membrane expressing glucose isomerase with chitosan
  • sample 1 Take the 2cm ⁇ 2cm immobilized glucose isomerase membrane (sample 1) prepared by the above method and the immobilized glucose isomerase membrane (sample 2-5) prepared in Example 2-5, respectively, and soak them in 20 ml at room temperature. 30 minutes in ionized water. After soaking in deionized water, sample 1 is 2.7cm ⁇ 2.7cm; sample 2 is 2cm ⁇ 2cm; sample 3 is 2.3cm ⁇ 2.3cm; sample 4 is 2.5cm ⁇ 2.5cm; sample 5 is 2.4cm ⁇ 2.5cm (Fig. 1 to Figure 10).
  • the test results show that sodium trimetaphosphate, sodium pyrophosphate and sodium tripolyphosphate can effectively reduce the swelling degree of immobilized glucose isomerase membrane in contact with water.

Abstract

提供了膜状固定化细胞、多肽、寡肽或蛋白质及制备方法,包括1)提供未成膜的壳聚糖;2)提供未成膜的壳聚糖与细胞、多肽、寡肽或蛋白质的混合液;3)将交联剂与混合液混合;4)将共交联产物干燥,得到膜状固定化细胞、多肽、寡肽或蛋白质;其中,当步骤1)使用未经预交联的壳聚糖时,该方法还包括5)将膜状固定化细胞、多肽、寡肽或蛋白质与磷酸盐混合,使其中的壳聚糖分子之间进行交联。

Description

膜状固定化细胞、多肽、寡肽或蛋白质及其制备方法 技术领域
本发明属于固定化细胞和固定化蛋白领域,具体而言,涉及膜状固定化细胞、多肽、寡肽或蛋白质及其制备方法。
背景技术
酶的应用越趋广泛,而固定化酶因其易于与产品分离并可重复使用,所以常用于工业用途以减低生产成本。酶的固定化方法众多,如物理吸附、亲和联结、共价交联、凝絮包埋等(参见文献“Roger A.Sheldon,2007,Advanced Synthesis&Catalysis,349:1289-1307”)。
现有的载体的制作过程复杂,例如:制备硅载体需要使用多种有机溶液(袁中一、吴星佳、李士芸、吉鑫松,“一种珠状壳聚糖载体的制备及其应用于酶固定化的方法”,中国专利申请公开号:CN1407103A);制备多孔复合氧化物需要使用高温高压(权镐真、洪舜教、白桂东、金惠真、朴东坤,“多孔复合氧化物制造方法”,中国专利申请公开号:CN1171295A)。而一般凝胶载体制作过程简单,只需使把凝胶溶液用注射器滴入能使其凝胶化的溶液制成凝胶颗粒即可。例如:把海藻酸钠滴入氯化钙溶液、把卡拉胶滴入氯化钾溶液。不过这种技术在工业生产时需要设计特定的设备进行生产(曾昭景、欧阳平凯、潘光亮,“固定化细胞载体成型机”,中国专利申请公开号:CN2181511Y),这大大增加了生产成本。因此,制备简单及低生产成本的固定化方法一直是本领域研究人员的目标。
发明内容
为解决上述现有技术中所存在的问题,本发明提供了膜状固定化细胞、多肽、寡肽或蛋白质及其制备方法。
具体而言,本发明提供了:
(1)一种制备膜状固定化细胞、多肽、寡肽或蛋白质的方法,包括以下步骤:
1)提供未成膜的壳聚糖,其中所述壳聚糖为未经预交联的壳聚糖或经预交联的壳聚糖;
2)提供所述未成膜的壳聚糖与细胞、多肽、寡肽或蛋白质的混合液,其中在所述混合液中,所述未成膜的壳聚糖为溶解状态;
3)将交联剂与所述混合液混合,得到所述壳聚糖与所述细胞、多肽、寡肽或蛋白质的共交联产物;
4)将所述共交联产物干燥,得到膜状固定化细胞、多肽、寡肽或蛋白质;
其中,当步骤1)使用未经预交联的壳聚糖时,所述方法还包括:
5)将步骤4)所得膜状固定化细胞、多肽、寡肽或蛋白质与磷酸盐混合,使其中的壳聚糖分子之间进行交联。
(2)根据(1)所述的方法,其中通过将磷酸盐与未经预交联的壳聚糖混合来制备所述经预交联的壳聚糖。
(3)根据(1)或(2)所述的方法,其中所述磷酸盐与所述未经预交联的壳聚糖的重量比为(0.1-20):1。
(4)根据(1)或(2)所述的方法,其中所述磷酸盐选自多聚磷酸盐、多偏磷酸盐和焦磷酸盐中的一种或多种。
(5)根据(1)所述的方法,其中步骤3)中所述交联剂包括多元醛化合物和京尼平。
(6)根据(1)所述的方法,其中所述未成膜的壳聚糖包括壳聚糖粉末和壳聚糖溶液。
(7)根据(1)所述的方法,其中所述未成膜的壳聚糖为壳聚糖粉末,并且步骤2)包括,
I)提供壳聚糖粉末与细胞、多肽、寡肽或蛋白质的混合液;
II)用醋酸溶解所述壳聚糖粉末。
(8)根据(1)所述的方法,其中在步骤2)中,所述未成膜的壳聚糖与所述细胞的重量比为1:(1-20)。
(9)根据(1)所述的方法,其中在步骤2)中,所述未成膜的 壳聚糖与所述多肽、寡肽或蛋白质的重量比为(0.5-10):1。
(10)根据(1)所述的方法,其中在步骤3)中,所述交联剂与所述混合液中的未成膜的壳聚糖的重量比为(0.005-10):1。
(11)根据(1)所述的方法,其中所述蛋白质包括酶。
(12)根据(1)-(11)中任一项所述的方法制备的膜状固定化细胞、多肽、寡肽或蛋白质。
本发明与现有技术相比具有以下优点和积极效果:
本发明创新性地提出采用一步法制备膜状固定化细胞、多肽、寡肽或蛋白质。“一步法”是指使膜状壳聚糖载体的制备和细胞、多肽、寡肽或蛋白质的固定化同时完成,减少了制备载体的成本和时间,制备工艺简单,不需使用特定的仪器,易操作,适合工业化生产。
在本发明的方法中,细胞、多肽、寡肽、蛋白质或酶的载量可通过载体材料的用量灵活地控制。
本发明所用载体的主要成分为壳聚糖,其是一种天然无毒性的高份子聚合物,对环境不造成污染。
本发明采用磷酸盐使壳聚糖交联,可有效地降低膜状固定化细胞、多肽、寡肽、蛋白质或酶遇水膨胀的程度。并且磷酸盐是一种无害的食物添加剂,安全性可靠。
附图说明
图1示出实验例1中样本1在浸泡去离子水前的照片。
图2示出实验例1中样本1在浸泡去离子水后的照片。
图3示出实验例1中样本2在浸泡去离子水前的照片。
图4示出实验例1中样本2在浸泡去离子水后的照片。
图5示出实验例1中样本3在浸泡去离子水前的照片。
图6示出实验例1中样本3在浸泡去离子水后的照片。
图7示出实验例1中样本4在浸泡去离子水前的照片。
图8示出实验例1中样本4在浸泡去离子水后的照片。
图9示出实验例1中样本5在浸泡去离子水前的照片。
图10示出实验例1中样本5在浸泡去离子水后的照片。
具体实施方式
以下通过具体实施方式的描述并参照附图对本发明作进一步说明,但这并非是对本发明的限制,本领域技术人员根据本发明的基本思想,可以做出各种修改或改进,但是只要不脱离本发明的基本思想,均在本发明的范围之内。
本发明提供了一种制备膜状固定化细胞、多肽、寡肽或蛋白质的方法,包括以下步骤:
1)提供未成膜的壳聚糖,其中所述壳聚糖为未经预交联的壳聚糖或经预交联的壳聚糖;
2)提供所述未成膜的壳聚糖与细胞、多肽、寡肽或蛋白质的混合液,其中在所述混合液中,所述未成膜的壳聚糖为溶解状态;
3)将交联剂与所述混合液混合,得到所述壳聚糖与所述细胞、多肽、寡肽或蛋白质的共交联产物;
4)将所述共交联产物干燥,得到膜状固定化细胞、多肽、寡肽或蛋白质;
其中,当步骤1)使用未经预交联的壳聚糖时,所述方法还包括:
5)将步骤4)所得膜状固定化细胞、多肽、寡肽或蛋白质与磷酸盐混合,使其中的壳聚糖分子之间进行交联。
本发明利用了壳聚糖的成膜性制备了膜状固定化细胞、多肽、寡肽或蛋白质,其中的载体为膜状壳聚糖,即壳聚糖膜。在本文中,膜状固定化细胞、多肽、寡肽或蛋白质即为固定化细胞、多肽、寡肽或蛋白质膜,两种术语可互换使用。
通常,制备固定化细胞或酶的方法都是先制备载体,然后把细胞或酶以化学或物理方法固定在载体上。本发明的上述方法打破固有思路,使膜状壳聚糖载体的制备与细胞、多肽、寡肽或蛋白质的固定同时完成,把通常需要分开两步完成的工艺(载体制备和固定化)实现一步法完成,减少了制备载体的成本和时间。
另一方面,大部份具备成膜性的材料在成膜后存在遇水膨胀的问 题。交联成膜性材料则有助于降低膨胀程度,而常用的交联剂(例如环氧氯丙烷)具有一定毒性,因此在工业化应用方便受到很大的限制。本发明使用磷酸盐既解决了成膜后遇水膨胀的问题,又是一种环境友好的材料。
本文所用术语“壳聚糖”的结构是本领域已知的,其是一种氨基多糖,是非水溶性的,但可被醋酸溶解。
本文所用术语“未成膜的壳聚糖”是指该壳聚糖不是膜状的,也就是说,该壳聚糖不是固定化细胞、多肽、寡肽或蛋白质所需的膜状载体的状态。未成膜的壳聚糖可以为例如壳聚糖粉末或壳聚糖溶液。壳聚糖粉末或壳聚糖溶液均不是固定化细胞、多肽、寡肽或蛋白质的载体。
本文所用术语“未经预交联的壳聚糖”是指没有用交联剂处理过的自然状态下的壳聚糖。
本文所用术语“经预交联的壳聚糖”是指壳聚糖经磷酸盐处理,使壳聚糖的分子之间发生分子间交联。
在本发明中,所用壳聚糖的脱乙酰度为80%以上。
本发明所用术语“共交联”是指壳聚糖与细胞、多肽、寡肽或蛋白质之间发生交联作用,使细胞、多肽、寡肽或蛋白质与壳聚糖通过共价键结合,从而将细胞、多肽、寡肽或蛋白质固定在壳聚糖上。
本发明由于采用一步法进行载体制备和固定化过程,因此需考虑载体制备过程对细胞、蛋白质或酶活力的损失。为了减少磷酸盐处理对细胞、蛋白质或酶的影响,本发明优选预先用磷酸盐使壳聚糖交联,之后使用经预交联的壳聚糖制备膜状固定化细胞、蛋白质或酶。
预交联的壳聚糖可以通过使用磷酸盐与未经预交联的壳聚糖反应,使壳聚糖发生分子间交联来提供。可以在室温下将磷酸盐与未经预交联的壳聚糖混合合适的时间(例如30分钟)来制备所述预交联的壳聚糖。
优选地,所述磷酸盐选自多聚磷酸盐、多偏磷酸盐和焦磷酸盐中的一种或多种。
所述多聚磷酸盐优选为三聚磷酸钠。所述多偏磷酸盐优选为三偏 磷酸钠、六偏磷酸钠。所述焦磷酸盐优选为焦磷酸钠。
优选地,步骤3)所述的交联剂为多元醛化合物和京尼平。所述多元醛化合物包括戊二醛和双醛淀粉。
在一个优选的具体实施方案中,所述未成膜的壳聚糖为壳聚糖粉末,并且步骤2)包括,
I)提供壳聚糖粉末与细胞、多肽、寡肽或蛋白质的混合液;
II)用醋酸溶解所述壳聚糖粉末。
优选地,醋酸的终浓度为0.5%-10%(v/v)。
也可以先用醋酸溶解所述壳聚糖粉末,然后将溶解的壳聚糖与细胞、多肽、寡肽或蛋白质液混合。但上述先混合再溶解的实施方案能够使壳聚糖和细胞等充份混合,并且减少整体的体积,从而更有利于工业化生产。
在步骤2)中,所述未成膜的壳聚糖与所述细胞的重量比优选为1:(1-20);所述未成膜的壳聚糖与所述多肽、寡肽或蛋白质的重量比优选为(0.5-10):1。
在步骤3)中,所述交联剂与所述混合液中的未成膜的壳聚糖的重量比优选为(0.005-10):1。步骤3)可以在室温下进行合适的时间(例如10分钟)。
在步骤5)中,所述磷酸盐与所述未经预交联的壳聚糖的重量比优选为(0.1-20):1。
在预交联的情况中,磷酸盐与未经预交联的壳聚糖的重量比优选为(0.1-20):1。
在一个具体的实施方案中,本发明的方法包括以下依次进行的步骤:
a)将未经预交联的壳聚糖粉末与细胞、多肽、寡肽或蛋白质液混合;
b)添加醋酸溶解该壳聚糖;
c)添加多元醛化合物使该壳聚糖与细胞、多肽、寡肽或蛋白质交联;
d)将上述混合液干燥制成固定化细胞、多肽、寡肽或蛋白质膜;
e)将磷酸盐与上述固定化细胞、多肽、寡肽或蛋白质膜混合,使壳聚糖交联;
f)用去离子水清洗固定化细胞、多肽、寡肽或蛋白质膜,干燥后得到最终的固定化细胞、多肽、寡肽或蛋白质膜。
在另一个具体的实施方案中,本发明的方法包括以下依次进行的步骤:
A)制备经预交联的壳聚糖:
a)将未经预交联的壳聚糖粉末与磷酸盐溶液混合,使其与磷酸盐反应而发生交联;
b)将反应后的壳聚糖粉末过滤并清洗;
c)干燥后得经预交联的壳聚糖粉末;
B)将经预交联的壳聚糖粉末与细胞、多肽、寡肽或蛋白质液混合;
C)添加醋酸溶解该壳聚糖;
D)添加多元醛化合物使该壳聚糖与细胞、多肽、寡肽或蛋白质交联;
E)将上述混合液干燥,制得固定化细胞、多肽、寡肽或蛋白质膜。
在本发明中,所述蛋白质包括酶。
本发明还提供了用本发明的方法制备的膜状固定化细胞、多肽、寡肽或蛋白质,即固定化细胞、多肽、寡肽或蛋白质膜。
以下通过实施例的方式进一步解释或说明本发明内容,但这些实施例不应被理解为对本发明保护范围的限制。
例子
以下除非特别说明,否则以下例子中所用实验方法均使用本领域的常规实验流程、操作、材料和条件进行。
实施例1:以壳聚糖制备表达葡萄糖异构酶的固定化大肠杆菌细胞膜
取1g表达葡萄糖异构酶的大肠杆菌细胞(该大肠杆菌细胞的制备方法如公开号为CN1982445A的中国专利申请所述),重悬于9ml去离子水中,待细胞完全重悬后加0.1g壳聚糖粉末(潍坊科海甲壳素有限公司,脱乙酰度为95%);搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛(天津巿大茂化学试剂厂)溶液;反应10分钟后,把该混合液置培养皿室温干燥;干燥后浸泡于20ml 5%(w/v)三偏磷酸钠(pH 6.0)(上海阿拉丁生化科技股份有限公司)溶液中30分钟;用去离子水除去未反应的三偏磷酸钠,室温干燥后得表达葡萄糖异构酶的固定化大肠杆菌细胞膜0.46g。
称取以上述方法制备的表达葡萄糖异构酶的固定化大肠杆菌细胞膜10mg,加45%葡萄糖溶液(含4mM硫酸镁、180ppm偏重亚硫酸钠,pH 7.5)1ml,在振荡式培养箱中反应10分钟(60℃,振荡速度为1500转每分钟),置冰水终止反应。将所得的反应混合物用去离子水稀释10倍,然后用HPLC检测果糖含量(WATERS HPLC搭配Shodex SC1011柱和折射率侦测器,以去离子水为移动相,流速为1ml/分钟,温柱80℃进行样品分离)。通过检测发现,以上述反应条件下每分钟产生一微摩尔果糖为一单位,制得的表达葡萄糖异构酶的固定化大肠杆菌细胞膜的活力为182U/g。
实施例2:以壳聚糖制备固定化葡萄糖异构酶膜
取1g表达葡萄糖异构酶的大肠杆菌细胞重悬于4ml去离子水中,待细胞完全重悬后用超声波细胞破碎机于冰浴中把细胞破碎(超声功率50W,超声时间5秒,间隙时间5秒,循环30次),在4℃下以13000转每分钟离心20分钟,取上清液。把上清液的蛋白浓度以去离子水稀释至10mg/ml,取10ml加0.1g壳聚糖粉末;搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛溶液;反应10分钟后,把该混合溶液置培养皿中室温干燥;干燥后浸泡于20ml 5%(w/v)三偏磷酸钠(pH 6.0)溶液中30分钟;用去离子水除去未反应的三偏磷酸钠,室温干燥后得固定化葡萄糖异构酶膜0.25g。
称取按上述方法制备的固定化葡萄糖异构酶膜10mg,并按与上 述实施例1相同的方法进行检测,发现固定化葡萄糖异构酶膜活力为193U/g。
实施例3:以预交联壳聚糖制备固定化葡萄糖异构酶膜
取10g壳聚糖粉末,加400ml 1%三偏磷酸钠(pH 6.0);室温搅拌30分钟;过滤后用去离子水除去未反应的三偏磷酸钠;60℃干燥后得预交联壳聚糖9.7g。
取1g表达葡萄糖异构酶的大肠杆菌细胞重悬于4ml去离子水中,待细胞完全重悬后用超声波细胞破碎机于冰浴中把细胞破碎(超声功率50W,超声时间5秒,间隙时间5秒,循环30次),在4℃下以13000转每分钟离心20分钟,取上清液。把上清液的蛋白浓度以去离子水稀释至10mg/ml,取10ml加0.1g预交联壳聚糖粉末;搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛溶液;反应10分钟后,把该混合溶液置培养皿中;室温干燥后得固定化表达葡萄糖异构酶膜0.24g。
称取按上述方法制备的固定化葡萄糖异构酶膜10mg,并按与实施例1相同的方法进行检测,发现固定化葡萄糖异构酶膜活力为270U/g。
实施例4:以预交联壳聚糖制备固定化葡萄糖异构酶膜
取2g壳聚糖粉末,加80ml 1%焦磷酸钠(pH调至6);室温搅拌30分钟;过滤后用去离子水除去未反应的焦磷酸钠;60℃干燥后得预交联壳聚糖1.9g。
取1g表达葡萄糖异构酶的大肠杆菌细胞重悬于4ml去离子水中,待细胞完全重悬后用超声波细胞破碎机于冰浴中把细胞破碎(超声功率50W,超声时间5秒,间隙时间5秒、循环30次),于4℃以13000转每分钟离心20分钟,取上清液。把上清液的蛋白浓度以去离子水稀释至10mg/ml,取10ml加0.1g预交联壳聚糖粉末;搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛溶液;反应10分钟后,把该混合溶液置培养皿中;室温干燥后得固定化表达葡萄糖异构 酶膜0.23g。
称取按上述方法制备的固定化葡萄糖异构酶膜10mg,并按与实施例1相同的方法进行检测,发现固定化葡萄糖异构酶膜活力为250U/g。
实施例5:以预交联壳聚糖制备固定化葡萄糖异构酶膜
取2g壳聚糖粉末,加80ml 1%三聚磷酸钠(pH调至6);室温搅拌30分钟;过滤后用去离子水除去未反应的三聚磷酸钠;60℃干燥后得预交联壳聚糖1.9g。
取1g表达葡萄糖异构酶的大肠杆菌细胞重悬于4ml去离子水中,待细胞完全重悬后用超声波细胞破碎机于冰浴中把细胞破碎(超声功率50W,超声时间5秒,间隙时间5秒、循环30次),于4℃以13000转每分钟离心20分钟,取上清液。把上清液的蛋白浓度以去离子水稀释至10mg/ml,取10ml加0.1g预交联壳聚糖粉末;搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛溶液;反应10分钟后,把该混合溶液置培养皿中;室温干燥后得固定化表达葡萄糖异构酶膜0.22g。
称取按上述方法制备的固定化葡萄糖异构酶膜10mg,并按与实施例1相同的方法进行检测,发现固定化葡萄糖异构酶膜活力为200U/g。
实验例1:测试分别以三偏磷酸钠、焦磷酸钠和三聚磷酸钠交联壳聚糖的降低膨胀程度
取1g表达葡萄糖异构酶的大肠杆菌细胞重悬于4ml去离子水中,待细胞完全重悬后用超声波细胞破碎机于冰浴中把细胞破碎(超声功率50W,超声时间5秒,间隙时间5秒、循环30次),于4℃以13000转每分钟离心20分钟,取上清液。把上清液的蛋白浓度以去离子水稀释至10mg/ml,取10ml加0.1g壳聚糖粉末;搅拌下加50μl醋酸;充份混合后加0.25ml 1%(v/v)戊二醛溶液;反应10分钟后,把该混合溶液置培养皿中室温干燥,得固定化葡萄糖异构酶膜0.24g(对 照实验)。
分别取2cm×2cm按上述方法制备的固定化葡萄糖异构酶膜(样本1)和实施例2-5制备的固定化葡萄糖异构酶膜(样本2-5),在室温下浸泡于20ml去离子水中30分钟。浸泡去离子水后的样本1为2.7cm×2.7cm;样本2为2cm×2cm;样本3为2.3cm×2.3cm;样本4为2.5cm×2.5cm;样本5为2.4cm×2.5cm(图1至图10)。通过测试得出三偏磷酸钠、焦磷酸钠和三聚磷酸钠能有效降低固定化葡萄糖异构酶膜遇水膨胀的程度。

Claims (12)

  1. 一种制备膜状固定化细胞、多肽、寡肽或蛋白质的方法,包括以下步骤:
    1)提供未成膜的壳聚糖,其中所述壳聚糖为未经预交联的壳聚糖或经预交联的壳聚糖;
    2)提供所述未成膜的壳聚糖与细胞、多肽、寡肽或蛋白质的混合液,其中在所述混合液中,所述未成膜的壳聚糖为溶解状态;
    3)将交联剂与所述混合液混合,得到所述壳聚糖与所述细胞、多肽、寡肽或蛋白质的共交联产物;
    4)将所述共交联产物干燥,得到膜状固定化细胞、多肽、寡肽或蛋白质;
    其中,当步骤1)使用未经预交联的壳聚糖时,所述方法还包括:
    5)将步骤4)所得膜状固定化细胞、多肽、寡肽或蛋白质与磷酸盐混合,使其中的壳聚糖分子之间进行交联。
  2. 根据权利要求1所述的方法,其中通过将磷酸盐与未经预交联的壳聚糖混合来制备所述经预交联的壳聚糖。
  3. 根据权利要求1或2所述的方法,其中所述磷酸盐与所述未经预交联的壳聚糖的重量比为(0.1-20):1。
  4. 根据权利要求1或2所述的方法,其中所述磷酸盐选自多聚磷酸盐、多偏磷酸盐和焦磷酸盐中的一种或多种。
  5. 根据权利要求1所述的方法,其中步骤3)中所述交联剂包括多元醛化合物和京尼平。
  6. 根据权利要求1所述的方法,其中所述未成膜的壳聚糖包括壳聚糖粉末和壳聚糖溶液。
  7. 根据权利要求1所述的方法,其中所述未成膜的壳聚糖为壳聚糖粉末,并且步骤2)包括,
    I)提供壳聚糖粉末与细胞、多肽、寡肽或蛋白质的混合液;
    II)用醋酸溶解所述壳聚糖粉末。
  8. 根据权利要求1所述的方法,其中在步骤2)中,所述未成膜的壳聚糖与所述细胞的重量比为1:(1-20)。
  9. 根据权利要求1所述的方法,其中在步骤2)中,所述未成膜的壳聚糖与所述多肽、寡肽或蛋白质的重量比为(0.5-10):1。
  10. 根据权利要求1所述的方法,其中在步骤3)中,所述交联剂与所述混合液中的未成膜的壳聚糖的重量比为(0.005-10):1。
  11. 根据权利要求1所述的方法,其中所述蛋白质包括酶。
  12. 根据权利要求1-11中任一项所述的方法制备的膜状固定化细胞、多肽、寡肽或蛋白质。
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