Nanjo Yohei, Asatsuma Satoru, Itoh Kimiko, Hori Hidetaka, Mitsui Toshiaki
Graduate School of Science and Technology, Niigata University, Niigata, Japan.
Biosci Biotechnol Biochem. 2004 Jan;68(1):112-8. doi: 10.1271/bbb.68.112.
We isolated and identified 10 alpha-amylase isoforms by using beta-cyclodextrin Sepharose affinity column chromatography and two-dimensional polyacrylamide gel electrophoresis from germinating rice (Oryza sativa L.) seeds. Immunoblots with anti-alpha-amylase I-1 and II-4 antibodies indicated that 8 isoforms in 10 are distinguishable from alpha-amylase I-1 and II-4. Peptide mass fingerprinting analysis showed that there exist novel isoforms encoded by RAmy3B and RAmy3C genes. The optimum temperature for enzyme reaction of the RAmy3B and RAmy3C coding isoforms resembled that of alpha-amylase isoform II-4 (RAmy3D). Furthermore, complex protein polymorphism resulted from a single alpha-amylase gene was found to occur not only in RAmy3D, but also in RAmy3B.
我们利用β-环糊精琼脂糖亲和柱色谱法和二维聚丙烯酰胺凝胶电泳，从发芽的水稻（Oryza sativa L.）种子中分离并鉴定出10种α-淀粉酶同工型。用抗α-淀粉酶I-1和II-4抗体进行免疫印迹分析表明，10种同工型中有8种与α-淀粉酶I-1和II-4不同。肽质量指纹图谱分析表明，存在由RAmy3B和RAmy3C基因编码的新型同工型。由RAmy3B和RAmy3C编码的同工型的酶反应最佳温度与α-淀粉酶同工型II-4（RAmy3D）相似。此外，发现由单个α-淀粉酶基因导致的复杂蛋白质多态性不仅发生在RAmy3D中，也发生在RAmy3B中。
