近日,，由中國科學(xué)院昆明動(dòng)物研究所賴仞研究員領(lǐng)導(dǎo)的研究團(tuán)隊(duì)與中科院上海藥物研究所研究員林東海領(lǐng)導(dǎo)的研究團(tuán)隊(duì)在多肽類抗氧化系統(tǒng)研究方面獲新進(jìn)展。這是在2009年賴仞領(lǐng)導(dǎo)的研究團(tuán)隊(duì)提出基因編碼的多肽類抗氧化系統(tǒng),，并命名為“第三套抗氧化系統(tǒng)”的基礎(chǔ)上獲得的進(jìn)展,。研究表明，抗氧化多肽序列中的還原性半胱氨酸對快速清除自由基起著關(guān)鍵作用,。
據(jù)賴仞研究團(tuán)隊(duì)的博士研究生劉存寶介紹,，以前發(fā)現(xiàn)的兩大類皮膚抗氧化系統(tǒng)，一類為基因編碼的大分子抗氧化酶類,，如超氧化物歧化酶（SOD）,；另一類為小分子有機(jī)物，如維生素,。而兩棲類動(dòng)物是如何在陽光下富含氧氣的空氣環(huán)境中保持其裸露皮膚免受自由基的傷害,，不論從進(jìn)化的角度或?qū)?dòng)物皮膚生物學(xué)感興趣的研究者來說，都是個(gè)很重要和有趣的問題,。而關(guān)于這種防護(hù)機(jī)制的肽類系統(tǒng)研究尚待完善,。
在此基礎(chǔ)上，該研究團(tuán)隊(duì)從多肽類抗氧化系統(tǒng)對自由基的清除效率,、速度以及作用機(jī)理進(jìn)行了深入研究,。他們從一種名叫大綠蛙的皮膚中新發(fā)現(xiàn)了名為antioxidin-RL的抗氧化小肽，這為抗氧化肽系統(tǒng)在兩棲類動(dòng)物皮膚中可能廣泛存在提供了佐證,。antioxidin-RL具有強(qiáng)大的自由基清除能力,，可在2秒鐘內(nèi)清除一種名為ABTS的自由基的80%，比目前廣泛商業(yè)使用的抗氧化劑（如2,，6-二叔丁基-4-甲基苯酚和維生素E）快約2～4倍,，表明以antioxindin為代表的抗氧化肽類系統(tǒng)可能在保持兩棲類動(dòng)物皮膚的氧化還原反應(yīng)平衡中扮演重要角色。同時(shí),，通過氨基酸突變,、核磁共振實(shí)驗(yàn)和其他一系列生化試驗(yàn)證明，此小肽中位于第十位的半胱氨酸殘基在其快速清除自由基的能力中扮演重要角色,，而其中的酪氨酸則在小肽結(jié)合自由基的過程中起作用,。
目前，該研究結(jié)果發(fā)表在美國自由基生物醫(yī)學(xué)聯(lián)合會(huì)會(huì)刊Free Radical Biology & Medicine上,，相關(guān)成果已經(jīng)申請發(fā)明專利“大綠蛙抗氧化肽antioxidin-RL及其基因和應(yīng)用”,。該發(fā)明對生物醫(yī)學(xué)及化妝品研發(fā)具有重要意義,。(生物谷Bioon.com)
生物谷推薦原文出處：
Free Radical Biology and Medicine doi：10.1016/j.freeradbiomed.2010.01.036
Frog skins keep redox homeostasis by antioxidant peptides with rapid radical scavenging ability
Cunbao Liua, b, 1, Jing Hongb, c, 1, Hailong Yanga, b, 1, Jing Wua, b, Dongying Maa, b, Dongsheng Lia, Donghai Linc, , and Ren Laia, d, ,
a Biotoxin Unit of the Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
b Graduate School, Chinese Academy of Sciences, Beijing, China
c Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
d Key Laboratory of Microbiological Engineering of the Agricultural Environment, Ministry of Agriculture, Life Sciences College, Nanjing Agricultural University, Nanjing, Jiangsu, China
The question of how amphibians can protect themselves from reactive oxygen species when exposed to the sun in an oxygen-rich atmosphere is important and interesting, not only from an evolutionary viewpoint, but also as a primer for researchers interested in mammalian skin biology, in which such peptide systems for antioxidant defense are not well studied. The identification of an antioxidant peptide named antioxidin-RL from frog (Odorrana livida) skin in this report supports the idea that a peptide antioxidant system may be a widespread antioxidant strategy among amphibian skins. Its ability to eliminate most of the 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical tested within 2 s, which is much faster than the commercial antioxidant factor butylated hydroxytoluene, suggests that it has a potentially large impact on redox homeostasis in amphibian skins. Cys10 is proven to be responsible for its rapid radical scavenging function and tyrosines take part in the binding of antioxidin-RL to radicals according to our nuclear magnetic resonance assay.
