The activity of glycosidases is crucial for the function and biological activity of proteins conjugated with sugar moieties, which play an important role in adhesion of cells during attachment and detachment of the foetal membranes. The aim of study was to describe the ability of bovine placental tissues to break down O‐glycosidic bonds in different glycoproteins by the determination of activity of β‐galactosidase, α‐l‐fucosidase, β‐N‐acetyl‐hexosaminidase and sialidase in early–mid‐pregnancy as well as at parturition with released and retained foetal membranes. Moreover, the availability of substrates for these glycosidases in placental homogenates was evaluated. Placental samples were collected from pregnant (2–4 months) cows in slaughterhouse (n = 8) as well as during Caesarean section and divided into released foetal membranes (n = 8) and retained foetal membranes (n = 8). Tissue homogenates were subjected to spectrofluorimetric and spectrophotometric determinations of enzyme activities as well as electrophoretic separations. Enzyme activities expressed changes within examined time with significant (p < .05) differences between pregnancy and physiological parturition in β‐N‐acetyl‐hexosaminidase and α‐l‐fucosidase in foetal part of placenta while in maternal part only in the latter one. Decreasing tendency in enzyme activity was noticed in foetal part of retained samples in comparison with released ones with significant (p < .05) differences in α‐l‐fucosidase activity. The analysis of staining of sugar moieties attached to selected proteins depicted availability of sugar molecules in examined tissues, but their patterns differed between samples. In conclusion, sugar moieties in conjugated proteins express changes in the course of pregnancy which is reflected by the alterations in activities of placental glycosidases.

中文翻译：

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在有胎膜和无胎膜的情况下，怀孕和分娩期间所选糖苷酶的活性及其在牛胎盘中的底物的可用性。

糖苷酶的活性对于与糖部分缀合的蛋白质的功能和生物学活性至关重要，而糖部分在胎膜的附着和脱离过程中对细胞的粘附起着重要的作用。研究的目的是通过测定早期β-半乳糖苷酶，α-L-岩藻糖苷酶，β- N-乙酰基己糖胺酶和唾液酸酶的活性来描述牛胎盘组织分解不同糖蛋白中的O-糖苷键的能力。–妊娠中期以及分娩时胎膜被释放和保留。此外，评估了胎盘匀浆中这些糖苷酶底物的可用性。从屠宰场的怀孕母牛（2-4个月）收集胎盘样品（n = 8）以及在剖腹产时分为释放的胎膜（n  = 8）和保留的胎膜（n  = 8）。对组织匀浆进行荧光光谱和分光光度法测定酶活性以及电泳分离。酶活性在所检查的时间内表达出变化，胎盘的胎儿部分 中的β- N-乙酰基己糖胺酶和α-l-岩藻糖苷酶的妊娠和生理分娩之间存在显着（p <.05）差异，而孕产妇中只有后者。与显着（p）的释放样品相比，保留样品的胎儿部分注意到了酶活性的下降趋势。 <.05）α-1-岩藻糖苷酶活性的差异。附着于所选蛋白质的糖部分的染色分析显示了被检组织中糖分子的有效性，但样品之间的模式不同。总之，结合蛋白中的糖部分在妊娠过程中表达变化，这通过胎盘糖苷酶活性的变化反映出来。