Structural Characterization and Pro-inflammatory Activity of a Thaumatin-Like Protein from Pulp Tissues of Litchi chinensis
Structural Characterization and Pro-inflammatory Activity of a Thaumatin-Like Protein from Pulp Tissues of Litchi chinensis
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荔枝果肉组织中索马甜样蛋白的结构特征和促炎活性
DOI：
10.1021/acs.jafc.0c01320
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发表时间：
2020-06-10
影响因子：
6.1
通讯作者：
Zhao, Lei
中科院分区：
文献类型：
--
作者：
Chen, Huifang;Wang, Kai;Zhao, Lei
本研究旨在从荔枝果肉组织中提取和纯化蛋白质，并对其结构和促炎活性进行评价。结果表明，利用纳米LC-MS/MS鉴定了一种高纯度的荔枝蛋白为荔枝类奇异果甜蛋白（LcTLP），并对LcTLP基因进行了测序。分子量为24 kDa，主要二级结构为β折叠（33.00 +/- 2.86%）。小角X射线散射结果表明，LcTLP是一个球形颗粒（直径约140至165 nm），具有封闭的内部和粗糙的表面在溶液中。体外促炎活性测定显示，200 μ g/mL LcTLP刺激后，诱导型一氧化氮合酶和环氧合酶-2基因表达量分别达到9.71 ± 0.64和7.05 ± 1.00，分别是空白对照的7.05倍和9.61倍。LcTLP促进促炎细胞因子的基因表达和产生，包括肿瘤坏死因子-a和白细胞介素-1 β，并且它还增强p65的表达，p65是核因子-κ B信号通路的关键组分。此外，抗炎细胞因子白细胞介素-10和转化生长因子-β 1的水平在LcTLP刺激后增加。
The objective of this study was to extract and purify proteins from the pulp tissues of litchi and evaluate their structure and pro-inflammatory activity. The results showed that a highly pure litchi protein was identified as the litchi thaumatin-like protein (LcTLP) by nano LC-MS/MS and verified by sequencing of the LcTLP gene. The molecular weight was 24 kDa, and the main secondary structure was a beta sheet (33.00 +/- 2.86%). Small-angle X-ray scattering results showed that LcTLP was a spherical particle (diameter of approximately 140 to 165 nm) with a close internal and rough surface in solution. The assay of pro-inflammatory activity in vitro revealed that the expression of inducible nitric oxide synthase and cyclooxygenase-2 genes reached 9.71 +/- 0.64 and 7.05 +/- 1.00 after 200 mu g/mL LcTLP stimulation, which were 7.05-fold and 9.61-fold that of the blank control, respectively. LcTLP promoted the gene expression and production of pro-inflammatory cytokines, including tumor necrosis factor-a and interleukin-1 beta, and it also enhanced the expression of p65, which is a key component of nuclear factor-kappa B signaling pathways. Additionally, the levels of anti-inflammatory cytokines interleukin-10 and transforming growth factor-beta 1 increased after LcTLP stimulation.