Zhang Dandan, Wu Mengting, Guo Yuxing, Xun Mingyue, Wang Wenwen, Wu Zhen, Pan Daodong
Department of Food Science & Nutrition, Ginling College, Nanjing Normal University, Nanjing, PR China.
Key Laboratory of Animal Protein Deep Processing Technology of Zhejiang, Marine Science School, Ningbo University, Ningbo, Zhejiang, PR China.
J Sci Food Agric. 2017 Sep;97(12):4204-4209. doi: 10.1002/jsfa.8294. Epub 2017 Mar 31.
Surface-layer proteins (SLP) have been found in the outermost layer of the cell wall in many types of lactobacillus are considered to be an important factor with respect to intestinal immunity.
The present study compared the effects of SLP extracted by different concentrations of LiCl and carbamide, and subsequently identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, circular dichroism and differential scanning calorimetry. Furthermore, RAW 264.7 cells were used to evaluate the immunomodulatory effects of SLP. SLP were derived from Lactobacillus acidophilus CICC6074 with a molecular weight of 46 kDa, and consisted of 16.9% α-helix, 42.3% β-sheet, 20.8% β-turns and 22.5% random coils. SLP promoted NO secretion and higher quantities of NO were produced as the SLP concentrations increased. SLP concentrations over 50 µg mL significantly decreased the amount of tumor necrosis factor-α secreted by RAW264.7 cells.
SLP can trigger immunomodulatory effects in RAW 264.7 cells. This provides crucial information that will enable the further use of L. acidophilus in food, medicine and other products. © 2017 Society of Chemical Industry.
在许多类型的乳酸菌细胞壁最外层发现了表层蛋白（SLP），其被认为是影响肠道免疫的一个重要因素。
本研究比较了不同浓度的氯化锂和尿素提取的SLP的效果，随后通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、圆二色光谱和差示扫描量热法对其进行鉴定。此外，使用RAW 264.7细胞评估SLP的免疫调节作用。SLP来源于嗜酸乳杆菌CICC6074，分子量为46 kDa，由16.9%的α-螺旋、42.3%的β-折叠、20.8%的β-转角和22.5%的无规卷曲组成。SLP促进一氧化氮（NO）分泌，并且随着SLP浓度增加产生的NO量更高。浓度超过50 μg/mL的SLP显著降低RAW264.7细胞分泌的肿瘤坏死因子-α的量。
SLP可在RAW 264.7细胞中引发免疫调节作用。这提供了关键信息，将有助于嗜酸乳杆菌在食品、医药和其他产品中的进一步应用。© 2017化学工业协会。
