毕赤氏酵母醇氧化酶-2基因启动子突变体的分离和鉴定

巴斯毕赤我苯酵母表达系统已被广泛用于生产外源蛋白的寄主菌。利用该系统将外源基因整合交换到染色体上时，ＡＯＸ１基因被破力的甲醇利用缓慢，给发本报生产千古 定影响。在不改变现有表达系统前提下，从ＡＯＸＩ功能缺陷 株分离出Ｍｕｔ＾＋自发突变化突变体，通过突变体在甲醇培养基中生长曲线的测定，ＨＳＡ表达产物的聚丙烯酰胺凝胶电泳检测，证明突变体的甲醇利用能力和蛋白表达比原始菌株大大提高，突变体ＡＯＸ２基因上游

Isolation and Characterization of PAOX2 Mutant in Pichia pastoris

Spontaneous Mut mutants of P. pastoris AOX1-defective expression strain have been isolated, they were identified as phenotypically utilized methanol to grow as wild type. The results obtained from measuring growth curve when cultivated in medium in which methanol as a sole carbon souree and detecting HSA protein on SDS-PAGE confirmed that the mutants have increased ability to utilize methanol and express foreign HSA gene product. The promoter region of AOX2 gene from the mutants has been cloned by PCR amplification, and the DNA fragment is 1022bp in size. Sequencing analysis showed that there are two point mutations at positions of -529 and -255 from the translation initiation codon respectively. The mutations improved AOX-1 defective function and facilitate the foreign gene for higher expression.