O-acetylesterase activity of Bifidobacterium bifidum sialidase facilities the liberation of sialic acid and encourages the proliferation of sialic acid scavenging Bifidobacterium breve.
O-acetylesterase activity of Bifidobacterium bifidum sialidase facilities the liberation of sialic acid and encourages the proliferation of sialic acid scavenging Bifidobacterium breve.
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双歧杆菌唾液酸酶的 O-乙酰酯酶活性有利于唾液酸的释放，并促进唾液酸清除短双歧杆菌的增殖。
DOI：
10.1111/1758-2229.13083
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发表时间：
2022
影响因子：
3.3
通讯作者：
Okada N.
中科院分区：
文献类型：
--
作者：
Yokoi T;Nishiyama K;Kushida Y;Uribayashi K;Kunihara T;Fujimoto R;Yamamoto Y;Ito M;Miki T;Haneda T;Mukai T;Okada N.
两歧双歧杆菌具有两种细胞外唾液酸酶（SiaBb 1和SiaBb 2），可从粘蛋白唾液酸聚糖中释放游离唾液酸，可通过短双歧杆菌的交叉喂养来利用，否则将无法利用这种营养源。已知用O-乙酰基酯修饰唾液酸可保护粘蛋白聚糖免受细菌唾液酸酶降解。与SiaBb 2相比，SiaBb 1具有额外的O-乙酰酯酶（Est）结构域。我们的目的是阐明来自双歧杆菌的SiaBb 1 Est结构域在双歧杆菌内唾液酸交叉喂养中的作用。与His 6-SiaBb 2预处理相比，使用His 6-taged-Est和-SiaBb 2预处理牛颌下腺（BSM）分泌的粘蛋白释放了更高量的唾液酸。当补充His 6-Est-和His 6-SiaBb 2-处理的BSM时，短双歧杆菌的生长随着nanE表达的增加而增加。这些结果表明，SiaBb 1 Est结构域的酯酶活性增强了SiaBb 2从粘蛋白裂解唾液酸的效率。这种游离唾液酸可以通过共存的唾液酸清除剂短双歧杆菌交叉喂养来利用。在这里，我们提供了双歧杆菌独特的唾液酸聚糖降解特性的分子机制，这是由唾液酸交叉喂养背景下SiaBb 1和SiaBb 2的互补活性介导的。
Bifidobacterium bifidumpossesses two extracellular sialidases (SiaBb1 and SiaBb2) that release free sialic acid from mucin sialoglycans, which can be utilized via cross‐feeding byBifidobacterium brevethat, otherwise, is prevented from utilizing this nutrient source. Modification of sialic acids withO‐acetyl esters is known to protect mucin glycans from degradation by bacterial sialidases. Compared to SiaBb2, SiaBb1 has an additionalO‐acetylesterase (Est) domain. We aimed to elucidate the role of the SiaBb1 Est domain fromB.bifidumin sialic acid cross‐feeding withinBifidobacterium. Pre‐treatment of mucin secreted from bovine submaxillary glands (BSM) using His6‐tagged‐Est and ‐SiaBb2 released a higher amount of sialic acid compared to the pre‐treatment by His6‐SiaBb2. Growth ofB.breveincreased with an increase innanEexpression when supplemented with both His6‐Est‐ and His6‐SiaBb2‐treated BSM. These results indicate that the esterase activity of the SiaBb1 Est domain enhances the efficiency of SiaBb2 to cleave sialic acid from mucin. This free sialic acid can be utilized by coexisting sialic acid scavengingB.brevevia cross‐feeding. Here, we provide the molecular mechanism underlying the unique sialoglycan degradation property ofB.bifidumwhich is mediated by the complementary activities of SiaBb1 and SiaBb2 in the context of sialic acid cross‐feeding.