Resetting the ligand binding site of placental protein 13/galectin-13 recovers its ability to bind lactose
Resetting the ligand binding site of placental protein 13/galectin-13 recovers its ability to bind lactose
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重置胎盘蛋白13/galectin-13的配体结合位点可恢复其结合乳糖的能力
DOI：
10.1042/bsr20181787
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发表时间：
2018-11
影响因子：
4
通讯作者：
Zhou Yifa
中科院分区：
文献类型：
--
作者：
Su Jiyong;Cui Linlin;Si Yunlong;Song Chenyang;Li Yuying;Yang Tong;Wang Hao;Kevin Mayo;Tai Guihua;Zhou Yifa
胎盘蛋白13/半乳糖凝集素-13（Gal-13）在胎盘中高度表达，其中其较低表达与先兆子痫相关。最近，野生型Gal-13及其变体R53 H的高分辨率晶体结构得到了解决。晶体学和生化学结果表明，Gal-13和R53 H不能结合乳糖。在这里，我们使用定点突变来重新设计野生型Gal-13的配体结合位点，使其能够结合乳糖。在六个新的突变体中，我们能够解决其中四个的晶体结构。三种变体（R53 HH 57 R、R53 HH 57 RD 33 G和R53 HR 55 NH 57 RD 33 G）具有相同的两个突变（R53至H和H57至R），并且能够结合晶体中的乳糖，表明这些突变足以恢复Gal-13结合乳糖的能力。此外，R53 H和R53 HR 55 N的结构表明这些变体可以与Tris分子共结晶。令人惊讶的是，尽管这些变体以及野生型Gal-13都可以诱导血凝，但高浓度的乳糖不能抑制凝集，它们也不能结合乳糖修饰的Sepharose 6 b珠。总的来说，我们的结果表明Gal-3不是正常的半乳糖凝集素，其不能与β-半乳糖苷结合。最后，EGFP标记的野生型Gal-13及其变体在HeLa细胞中的分布表明，它们集中在细胞核中，并且可以共定位在细胞质内，可能是肌动蛋白。
Placental protein 13/galectin-13 (Gal-13) is highly expressed in placenta, where its lower expression is related to pre-eclampsia. Recently, the crystal structures of wild-type Gal-13 and its variant R53H at high resolution were solved. The crystallographic and biochemical results showed that Gal-13 and R53H could not bind lactose. Here, we used site-directed mutagenesis to re-engineer the ligand binding site of wild-type Gal-13, so that it could bind lactose. Of six newly engineered mutants, we were able to solve the crystal structures of four of them. Three variants (R53HH57R, R53HH57RD33G and R53HR55NH57RD33G had the same two mutations (R53 to H, and H57 to R) and were able to bind lactose in the crystal, indicating that these mutations were sufficient for recovering the ability of Gal-13 to bind lactose. Moreover, the structures of R53H and R53HR55N show that these variants could co-crystallize with a molecule of Tris. Surprisingly, although these variants, as well as wild-type Gal-13, could all induce hemagglutination, high concentrations of lactose could not inhibit agglutination, nor could they bind to lactose-modified Sepharose 6b beads. Overall, our results indicate that Gal-3 is not a normal galectin, which could not bind to β-galactosides. Lastly, the distribution of EGFP-tagged wild-type Gal-13 and its variants in HeLa cells showed that they are concentrated in the nucleus and could be co-localized within filamentary materials, possibly actin.
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DOI：
10.2210/pdb1hlc/pdb
发表时间：
1994-04
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Y. Lobsanov;M. Gitt;H. Leffler;S. Barondes;J. Rini
通讯作者：
Y. Lobsanov;M. Gitt;H. Leffler;S. Barondes;J. Rini
确定人半乳糖凝集素 10 的配体结合特异性、同源二聚化和细胞分布的关键氨基酸残基的鉴定
影响因子：
4.3
作者：
Su Jiyong;Song Chenyang;Si Yunlong;Cui Linlin;Yang Tong;Li Yuying;Wang Hao;Tai Guihua;Zhou Yifa
通讯作者：
Zhou Yifa
影响因子：
3.8
作者：
Than NG;Romero R;Xu Y;Erez O;Xu Z;Bhatti G;Leavitt R;Chung TH;El-Azzamy H;LaJeunesse C;Wang B;Balogh A;Szalai G;Land S;Dong Z;Hassan SS;Chaiworapongsa T;Krispin M;Kim CJ;Tarca AL;Papp Z;Bohn H
通讯作者：
Bohn H
影响因子：
10.7
作者：
Houzelstein, D;Gonçalves, IR;Poirier, F
通讯作者：
Poirier, F
影响因子：
2.9
作者：
Sekizawa, Akihiko;Purwosunu, Yuditiya;Farina, Antonio
通讯作者：
Farina, Antonio