Matters G L, Boyer C D
Biochem Genet. 1982 Oct;20(9-10):833-48. doi: 10.1007/BF00484061.
Soluble starch synthase and branching enzyme were purified from 18-day-old cotyledons of the smooth-seeded pea cultivar Alaska (RR) and wrinkled-seeded pea cultivar Progress #9 (rr) by DEAE-cellulose chromatography. Two coeluting peaks of primed and citrate-stimulated starch synthase activity and a major and minor peak of branching enzyme activity were observed in Alaska. However, in Progress #9, only one peak of synthase activity was found. When crude extracts of Progress #9 were centrifuged, over 70% of the starch synthase activity was recovered in the pelleted fraction, and additional washings of the pellet released no further activity. The addition of purified starch granules to Alaska crude extracts also resulted in the recovery of a greater proportion of synthase activity in pelleted fractions. The two peaks of branching enzyme activity in Alaska differed in their stimulation of phosphorylase, amylose branching activity, and activity in various buffers. The DEAE-cellulose profile of Progress #9 showed no distinct peak of branching enzyme and less than 10% of the total activity found in Alaska. The association of one form of soluble starch synthase with the pelleted fraction and the greatly reduced levels of branching enzyme provide a partial explanation for the appearance of high-amylose starch in Progress #9 cotyledons.
通过DEAE - 纤维素色谱法从光滑种子豌豆品种阿拉斯加（RR）和皱粒种子豌豆品种Progress #9（rr）的18日龄子叶中纯化了可溶性淀粉合酶和分支酶。在阿拉斯加观察到引发的和柠檬酸刺激的淀粉合酶活性的两个共洗脱峰以及分支酶活性的一个主峰和一个次峰。然而，在Progress #9中，仅发现一个合酶活性峰。当对Progress #9的粗提物进行离心时，超过70%的淀粉合酶活性在沉淀部分中回收，并且对沉淀进行额外洗涤不会释放出更多活性。向阿拉斯加粗提物中添加纯化的淀粉颗粒也导致沉淀部分中更大比例的合酶活性得以回收。阿拉斯加分支酶活性的两个峰在对磷酸化酶的刺激、直链淀粉分支活性以及在各种缓冲液中的活性方面存在差异。Progress #9的DEAE - 纤维素图谱未显示出明显的分支酶峰，且其总活性不到阿拉斯加的10%。一种形式的可溶性淀粉合酶与沉淀部分的结合以及分支酶水平的大幅降低为Progress #9子叶中高直链淀粉淀粉的出现提供了部分解释。
