细胞技术

Covalent binding of an enzyme to a support is probably the most interesting method of immobilization from an industrial point of view. In this methodology, the activated groups of the support react with some external functional groups of the protein (see Chapter 1). Generally, reaction betwe ...

Adsorption is a very economical procedure for immobilization of enzymes. The stability of the adsorbed enzyme derivative will depend on the strength of the noncovalent bonds formed between the support and the amino acid residues on the surface of the protein. Two principal types of bonds can be f ...

Coimmobilization of cells and/or enzymes is performed for three main reasons: first, to enable cells to use other, nonmetabolizable substrates than the natural ones of the corresponding strain (1,2); second, to enlarge the product spectrum by utilization of the catalytic capabilities of ...

Polyelectrolyte complexes are rapidly formed when oppositely charged polyions are mixed. There are two basic principles making use of polyelectrolyte complexes for immobilization of cells and enzymes—entrapment and microen-capsulation. Because the entrapment in polyel ...

Carbonyldiimidazole (CDI) activated supports for enzyme immobilization are commercially available. The urethane linkage that is formed when a protein is bound to these supports is about 20-fold more stable than the N-substituted isourea linkage formed during protein immobiliz ...

For many years, chemical modification of enzymes has been a key technique to elucidate the residues involved in their catalytic activity. More recently, chemical modification has also been a useful tool in applied biochemistry (e.g., enzyme stabilization by modification of key residue ...

Immobilization of enzymes on pre-existing supports containing small aliphatic aldehyde groups (e.g., glyoxyl-agarose) presents a set of interesting features from both a basic and a more practical point of view. The chemistry of this immobilization method is quite different from more p ...

The immobilization of proteins is an essential step in constructing affinity purification or enzyme reactor systems. For these biotechnological processes, immobilized proteins can be used in either batchwise or column operations. Commonly utilized insoluble supports for pr ...

Immobilization of enzymes and cells has been widely investigated for many years, and numerous studies and reviews have appeared in the literature. In fact, immobilization offers the possibility to improve stability of the catalyst and is also considered the simplest and most effective m ...

Entrapment of enzymes and/or cells in alginate is one of the simplest methods of immobilization. Alginates are available commercially as water-soluble sodium alginates, and have been used for more than 65 years in the food and pharmaceutical industries as thickening, emulsifying, film f ...

Immobilization in carrageenans is a method of gel entrapment. It is one of the most widely used methods for cell immobilization because it is cheap, simple, and reproducible with mild conditions during the immobilization. The major advantages of the entrapment method are high cell density, m ...

Immobilization of enzymes is a basic technique that is well established in very different fields of both research and industry. The actual knowledge of the basic principles for immobilizing enzymes is so broad that one can design the immobilized enzyme to accomplish a given task or to show prope ...

Nylons are a family of linear condensation polymers, involving the repeated alkane segments bound by secondary amide linkages. The different types of nylons available commercially are named and classified according to the number of carbon atoms in their monomeric units (i.e., nylon 6,6 is o ...

The use of transition metal chemistry for the immobilization of biological molecules is long established and well documented (1–17). This method is based on the chelation properties of transition metals, namely titanium(IV) and zirconium(IV), which seem particularly attractive on a ...

Immobilization of a protein through coordinate bonds formed with divalent metal ions (e.g., Me(II), Cu(II)) is becoming an attractive alternative to covalent coupling chemistries. This is primarily a result of the reversible nature of the immobilization, because the protein may be easily ...

Owing to the nearly limitless diversity of immunoglobulin (Ig) variable-region gene rearrangements, such rearrangements represent ideal clonal markers for B-lineage cells. This chapter describes an approach to isolate single cells from frozen tissue sections by microdisse ...

The term apoptosis was coined in a now classic paper by Kerr et al. in 1972 (1), which summarized the morphological features observed in electron micrographs of cells dying by a process that had been previously termed shrinkage necrosis. It was noted that these features, such as cell shrinkage, nucle ...

The ability to capture and visualize information throughout the volume of a living three-dimensional (3-D) specimen as it changes over time (four-dimensional imaging) has been the goal of many biological researchers. In practice, this is usually accomplished by gathering a series of 3-D da ...

Proteases act as the molecular mediators of many vital biological processes. To understand the function of each protease, it needs to be separated from other proteins and characterized in its natural, biologically active form. In the method described in this chapter, proteases in a biologi ...

Human papillomavirus (HPV) is a highly prevalent sexually transmitted virus that causes genital warts in men and women and is associated with an increased risk of genital tract neoplasia in women (1,2). Nucleic acid amplification techniques such as the polymerase chain reaction (PCR) have ...