Winkler U K, Stuckmann M
J Bacteriol. 1979 Jun;138(3):663-70. doi: 10.1128/jb.138.3.663-670.1979.
Among 21 different polysaccharides tested, 5 greatly enhanced the spontaneous and cyclic AMP-induced formation of exolipase: glycogen, hyaluronate, laminarin, pectin B, and gum arabic. These polysaccharides have in common the tendency to form highly ordered networks because of the branching or helical arrangement, or both, of their molecules. None of the polysaccharides could be utilized by the cells as the sole carbon source. Strong lipid extraction of four different polysaccharides did not reduce their exolipase-enhancing efficacy. At a constant cell density the stimulation of exolipase formation by various concentrations of glycogen followed saturation kinetics, suggesting a limited number of "sites" for the glycogen to act. The active principle present in a solution of pectin was destroyed by degradation (beta-elimination) of the polymer. Hyaluronate lost its exolipase-enhancing activity by exhaustive hydrolysis with hyaluronidase but was resistant to proteinase K. Exopolysaccharide, isolated from growth medium of Serratia marcescens SM-6, enhanced the exolipase formation as efficiently as hyaluronate. The results of this work are discussed mainly in terms of the "detachment hypothesis."
在测试的21种不同多糖中，有5种能显著增强外切脂肪酶的自发形成以及由环磷酸腺苷诱导的外切脂肪酶形成：糖原、透明质酸盐、海带多糖、果胶B和阿拉伯树胶。这些多糖的共同特点是，由于其分子的分支或螺旋排列，或两者兼具，它们倾向于形成高度有序的网络。这些多糖都不能被细胞用作唯一的碳源。对四种不同多糖进行强力脂质提取并未降低它们增强外切脂肪酶的功效。在细胞密度恒定的情况下，不同浓度的糖原对外切脂肪酶形成的刺激遵循饱和动力学，这表明糖原发挥作用的“位点”数量有限。果胶溶液中的活性成分会因聚合物的降解（β-消除）而被破坏。透明质酸盐经透明质酸酶彻底水解后失去了其增强外切脂肪酶的活性，但对蛋白酶K具有抗性。从粘质沙雷氏菌SM-6生长培养基中分离出的胞外多糖增强外切脂肪酶形成的效率与透明质酸盐相同。本文主要根据“分离假说”对这项工作的结果进行了讨论。
