Institute of Cardiology, Jagiellonian University Medical College, Cracow, Poland; John Paul II Hospital, Cracow, Poland.
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Biochem Biophys Res Commun. 2020 Jan 1;521(1):19-23. doi: 10.1016/j.bbrc.2019.09.144. Epub 2019 Oct 23.
The post-translational protein modification via lysine residues can significantly alter its function. α2-antiplasmin, a key inhibitor of fibrinolysis, contains 19 lysine residues.
We sought to identify sites of glycation and acetylation in human α2-antiplasmin and test whether the competition might occur on the lysine residues of α2-antiplasmin.
We analyzed human α2-antiplasmin (1) untreated; (2) incubated with increasing concentrations of β-d-glucose (0, 5, 10, 50 mM); (3) incubated with 1.6 mM acetylsalicylic acid (ASA) and (4) incubated with 1.6 mM ASA and 50 mM β-d-glucose, using the ultraperformance liquid chromatography system coupled to mass spectrometer.
Eleven glycation sites and 10 acetylation sites were found in α2-antiplasmin. Incubation with β-d-glucose was associated with glycation of 4 (K-418, K-427, K-434, K-441) out of 6 lysine residues, known to be important for mediating the interaction with plasmin. Glycation and acetylation overlapped at 9 sites in samples incubated with β-d-glucose or ASA. Incubation with concomitant ASA and β-d-glucose was associated with the decreased acetylation at all sites overlapping with glycation sites. At K-182 and K-448, decreased acetylation was associated with increased glycation when compared with α2-antiplasmin incubated with 50 mM β-d-glucose alone. Although K-24 located in the proximity of the α2-antiplasmin cleavage site, was found to be only acetylated, incubation with ASA and 50 mM β-d-glucose was associated the absence of acetylation at that site.
Human α2-antiplasmin is glycated and acetylated at several sites, with the possible competition between acetylation and glycation at K-182 and K-448. Our finding suggests possibly relevant alterations to α2-antiplasmin function at high glycemia and during aspirin use.
赖氨酸残基的翻译后蛋白质修饰可以显著改变其功能。α2-抗纤溶酶是纤维蛋白溶解的关键抑制剂，含有 19 个赖氨酸残基。
我们试图确定人α2-抗纤溶酶中糖基化和乙酰化的位点，并测试这种竞争是否可能发生在α2-抗纤溶酶的赖氨酸残基上。
我们使用超高效液相色谱系统与质谱仪联用，分析了未经处理的人α2-抗纤溶酶（1）；（2）与β-d-葡萄糖（0、5、10、50 mM）浓度递增孵育；（3）与 1.6 mM 乙酰水杨酸（ASA）孵育；（4）与 1.6 mM ASA 和 50 mM β-d-葡萄糖孵育。
在α2-抗纤溶酶中发现了 11 个糖基化位点和 10 个乙酰化位点。与β-d-葡萄糖孵育与 6 个赖氨酸残基中的 4 个（K-418、K-427、K-434、K-441）的糖基化有关，这 4 个赖氨酸残基对介导与纤溶酶的相互作用很重要。在与β-d-葡萄糖或 ASA 孵育的样品中，有 9 个位点发生糖基化和乙酰化重叠。同时孵育 ASA 和β-d-葡萄糖与重叠糖基化位点的所有位点的乙酰化减少有关。与单独用 50 mM β-d-葡萄糖孵育的α2-抗纤溶酶相比，K-182 和 K-448 的乙酰化减少与糖基化增加有关。尽管位于α2-抗纤溶酶切割位点附近的 K-24 仅被乙酰化，但与 ASA 和 50 mM β-d-葡萄糖孵育时，该位点的乙酰化不存在。
人α2-抗纤溶酶在几个位点发生糖基化和乙酰化，在 K-182 和 K-448 处，乙酰化和糖基化之间可能存在竞争。我们的发现表明，在高血糖和使用阿司匹林期间，α2-抗纤溶酶的功能可能会发生相关改变。
