编译：沧浪之水2010，小顾营养
ScienceDaily (Dec. 5, 2009) 科学日报（09年12月5日） -新伊利诺斯大学的两份新研究报告指出lunasin这种往往弃置于大豆加工厂废物流的大豆肽，可能对保健有很重要作用，包括抗白血病，阻止糖尿病、心脏病及中风等慢性病的并发炎症。
致力食品科学和人类营养学研究的Elvira de Mejia教授说："我们通过一个额外研究证实了 lunasin在人体中的生物利用度。研究中，一名男性每天饮用50克大豆蛋白和1份大豆奶昔，吃一份大豆辣椒，共持续5天 。参加者血液中显著的多肽水平使我们相信，富含lunasin的大豆食品在提供这些健康收益方面可以起重要作用。
在癌症研究中，德梅希亚的研究组鉴定了关键的氨基酸序列-精氨酸，甘氨酸和天门冬氨酸（RGD基序） -这通过激活蛋白caspase – 3而触发白血病细胞的死亡。
“其他科学家注意到氨基酸的RGD序列预防癌症的作用，因此重要的是要找到有这种序列的蛋白质，”她说。
科学家们还证实lunasin在抑制拓扑异构酶2 这种标志着癌症发展的酶的作用。他们还能够确定在实验室中通过lunasin治疗后被杀死的白血病细胞数量。
另一项研究首次报告了lunasin的潜在抗炎活性，他们发现lunasin阻止或减少了一种重要的标记物，即所谓的核因子kappa - B的活性，这是导致炎症的一种生化反应序列的链接标志。
"虽然炎症是与在公众心目中与慢性健康问题，如心脏病、糖尿病、类风湿性关节炎等有关，德梅希亚说，炎症在癌症发展中也有作用。“我们知道，慢性炎症使患恶性肿瘤的危险增加，它是一个在肿瘤生长过程中的关键因素，”她说。
她补充说，“我们可以看到，丰富的大豆蛋白提供了lunasin的日常消耗，可能有助于减少慢性炎症。今后的研究应该可以为我们提供饮食建议。
她说，虽然从大豆废料获得lunasin的高成本限制了它的在调配营养中的使用，但是豆粉含有高浓度的多肽。
补充资料：
Lunasin is a unique 43-amino acid soybean peptide that contains at its carboxyl end: (a) nine Asp (D) residues; (b) an Arg-Gly-Asp (RGD) cell adhesion motif; and (c) a predicted helix with structural homology to a conserved region of chromatin-binding proteins.
Isolation, Purification And Characterisation Of Lunasin From Defatted Soybean Flour And In Vitro Evaluation Of Its Anti-inflammatory Activity
References: 31 Times Cited: 1
Author(s):
Dia V P
Wang W
Oh V L
Lumen B O de
Gonzalez E de Mejia
Abstract:
Lunasin is a chemopreventive peptide present in soybean and other plant sources. The high cost involved in obtaining synthetic lunasin limits its application in chemopreventive and nutritional interventions. The objective of this study was to isolate, purify and characterise lunasin from defatted soybean flour and determine its in vitro anti-inflammatory activity using RAW 264.7 macrophages. Isolation and purification was achieved by ion-exchange chromatography, ultrafiltration and size exclusion chromatogra-phy. The identity of lunasin was established by Western blot, HPLC, MALDI-TOF and LC/MS-MS. The results showed that lunasin eluted from a DEAE anion exchange column at 0.15 M NaCl, and after 1.5 void volumes from size exclusion chromatography. Fractions from both chromatographic techniques consistently showed three peptides with positive immunoreactivity against lunasin mouse monoclonal antibody corresponding to 5, 8 and 14 kDa. LC/MS-MS analysis of the three immunoreactive peptides showed that 5 and 14 kDa bands contained the lunasin epitope, RGDDDDDD DDD while 8 kDa band showed high homology with 2 S soy albumin, a lunasin precursor. This is the first report on the potential anti-inflammatory activity of lunasin. Treatment of RAW 264.7 macrophage with 100 ?M lunasin decreased the production of NO (92.6 ?0.8%) and PGE_2 (10.1 ?.5%), and the expression of iNOS (27.8 ?2.1%) and COX-2 (41.4 ?16.7%). We concluded that combination of ion-exchange chromatography, ultrafiltration and size exclusion chromatography represents a feasible process for the production of purified lunasin, which was also found to inhibit COX-2/PGE_2 and iNOS/ NO pathways. This newly discovered property of lunasin might contribute to the suppression of inflammation in vivo.
Source:
Food Chemistry , 2009, 114 (1) : 108-115
ISSN:
0308-8146
Language:
English
Keywords:
lunasin ; purification ; inflammation ; cox-2/pge_2 ; inos/no ; TS201
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