Cell surface engineering

在细胞表面，许多受体蛋白被提呈，这些受体蛋白识别特定的生物分子。这些机理可以从化学角度进行分析。为了使生物设计系统化，对细胞表面设计进行了研究。田中博士研究了用酶和功能蛋白(糖淀粉酶、α-淀粉酶、CM-纤维素酶、β-葡萄糖苷酶、脂肪酶)武装起来的新型酵母细胞的开发，这是一种组氨酸低聚物。绿色荧光蛋白及其变体)。酵母是由酵母细胞表面工程系统构建的，该系统可以吸收多余的生物量或展示疫苗蛋白。这些表面工程酵母细胞被称为“武装酵母”。“细胞表面工程”将能够赋予活细胞新的额外能力，并将预示着生物技术领域的一个新纪元。Nagamune博士研究了一种改变生长因子结合元件的方法，以改变其特定配体-受体对的特异性。通过将抗鸡蛋溶菌酶(HEL)抗体HyHEL-10的抗体可变区VH和VL与促红细胞生成素受体(EPOR)的胞浆部分连接，形成了可被HEL激活的嵌合受体。当IL-3依赖的小鼠髓系32D细胞与编码VH-EPOR和VL-EPOR-IRES-EGFP的载体共转染时，HEL诱导高表达EGFP的细胞群的选择性扩增。为了扩展目前的方法，开发了胞浆结构域被GP 130取代的嵌合受体。Akiyoshi博士使用脂质体展示系统作为模型生物膜研究了细胞表面糖的功能。结果表明：1)神经节苷脂结合脂质体的作用；2)用疏水多糖包覆植基磷酸巨囊泡的作用；3)神经节苷脂存在下细胞大小脂质体的动态形态变化。

In cell surface, many recepter proteins are presented and the specific biomolecules are recognized by these recepter proteins. These mechanisms can be analyzed from chemical view points. To systemize the biotergeting, the cell sueface design was investigated. Dr. Tanaka studied the development of novel yeast cells armed with enzymes and functional proteins (glucoamylase, α-amylase, CM-cellulase, β-glucosidase, lipase, a histidine oligomer. green fluorescent protein, and its variants). The yeasts were constructed by a cell surface engiseering system of yeast Sacebaromyces cerevisiae, which can assimilate the redundant biomass or can display the vaccine protein. These surface-engineered yeast cells are termed as "Arming yeasts". "Cell surface engineering" will be capable of conferring novel additional abilities upon living cells and will herald a new era in the field of biotechnology. Dr. Nagamune Studied a way of changing the binding element of a growth factor so as to alter its specificity of specific ligand-receptor pairs. By joining these antibody variable domains, VH and VL, of anti-hen egg lysozyme (HEL) antibody HyHEL-10 to the cytoplasmic portion of erythropoietin receptor (EpoR), a chimeric receptor that could he activated by HEL was developed. When IL-3-dependent murine myeloid 32D cells were co-transfected with plasmids encoding VH-EpoR and VL-EpoR-IRES-EGFP, HEL induced selective expansion of the cell population with high expression level of EGFP. To expand the current approach, chimeric receptors whose cytoplasmic domain was replaced by that of gp 130 were developed. Dr. Akiyoshi studied the functions of cell-surface saccharides using liposomal displaying systems as model biological membrane. It was demonstrated that 1) function of gangliosides-conatining liposomes, 2) coating of phytylphosphate giant vesicles with a hydrophobized polysaccharide 3) dynamic morphological changes of cell-size liposomes in the presence of gangliosides.