Holmes E, Boyer C, Preiss J
J Bacteriol. 1982 Sep;151(3):1444-53. doi: 10.1128/jb.151.3.1444-1453.1982.
Escherichia coli B glycogen synthase and branching enzyme, although similar in amino acid composition, had no significant immunological cross-reactivity. The N-terminal sequences of the glycogen synthase were rich in hydrophobic residues, whereas branching enzyme had a higher content of acidic and basic residues. However, residues 21 to 28 of glycogen synthase and 7 to 14 of branching enzyme shared six of eight residues in common. Two fractions of branching enzyme, branching enzymes I and II, which can be isolated from E. coli B cell extracts, have been shown to be immunologically identical, suggesting that only one type of branching enzyme activity is present in E. coli B. Evidence has been obtained which indicates that E. coli B glycogen synthase and branching enzyme are antigenically very similar to glycogen synthases and branching enzymes from other enteric bacteria. No cross-reactivity with either enzyme was observed in cell extracts from photosynthetic bacteria.
大肠杆菌B糖原合酶和分支酶虽然氨基酸组成相似，但没有明显的免疫交叉反应性。糖原合酶的N端序列富含疏水残基，而分支酶的酸性和碱性残基含量较高。然而，糖原合酶的第21至28位残基与分支酶的第7至14位残基共有八个残基中的六个。可以从大肠杆菌B细胞提取物中分离出的两种分支酶组分，即分支酶I和II，已被证明在免疫上是相同的，这表明大肠杆菌B中仅存在一种类型的分支酶活性。已经获得的证据表明，大肠杆菌B糖原合酶和分支酶在抗原性上与其他肠道细菌的糖原合酶和分支酶非常相似。在光合细菌的细胞提取物中未观察到与任何一种酶的交叉反应性。
