Department of Chemistry, University of Colorado, Boulder, Colorado 80302.
Plant Physiol. 1972 Mar;49(3):293-8. doi: 10.1104/pp.49.3.293.
Cultures of Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner have been induced to secrete an endopolygalacturonase (polygalacturonide glycanohydrolase EC3.2. 1.15). This enzyme has been brought to a high state of purity by ion exchange, gel filtration, and agarose affinity chromatography. The enzyme has optimal activity at pH 5, has an apparent molecular weight as determined by gel filtration of about 70,000, and prefers polygalacturonic acid to pectin as its substrate. The enzyme, while hydrolyzing only 1% of the glycosidic bonds, reduces the viscosity of a polygalacturonic solution by 50%. Nevertheless, the initial as well as the final products of polygalacturonic acid hydrolysis are predominantly tri- and digalacturonic acid and, to a lesser extent, monogalacturonic acid. The purified enzyme catalyzes the removal of about 80% of the galacturonic acid residues of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus) as well as from the walls isolated from 8-day-old Red Kidney bean (Phaseolus vulgaris) hypocotyls.
已诱导炭疽菌（Saccardo 和 Magnus）Scribner 培养物分泌内切多聚半乳糖醛酸酶（多聚半乳糖醛酸聚糖水解酶 EC3.2.1.15）。该酶已通过离子交换、凝胶过滤和琼脂糖亲和层析达到高度纯度。该酶在 pH5 时具有最佳活性，通过凝胶过滤测定的表观分子量约为 70,000，并且更喜欢聚半乳糖醛酸作为其底物而不是果胶。该酶虽然仅水解 1%的糖苷键，但可将聚半乳糖醛酸溶液的粘度降低 50%。尽管如此，聚半乳糖醛酸水解的初始和最终产物主要是三糖和二糖醛酸，并且程度较小的是单糖醛酸。纯化的酶可催化从悬浮培养的枫香细胞（Acer pseudoplatanus）细胞壁以及从 8 天大的红芸豆（Phaseolus vulgaris）下胚轴细胞壁中分离的细胞壁中去除约 80%的半乳糖醛酸残基。
