病原體感染是包括植物的高等生物的主要健康危害之一。為抵禦入侵者,大多數植物會製造防禦蛋白,包括凝集素、蛋白酶抑製劑、抗真菌蛋白、核糖核酸酶和核糖體失活蛋白,並分佈在不同的器官,如葉、根、種子和塊莖。一些植物防禦蛋白被發現能表現出多種生物活性,如抗腫瘤活性、抗細菌活性和抗病毒活性,能抵抗多種植物病原菌和人類病原體。因此,一些植物防禦蛋白可能有潛力用於治療人類疾病,或保護農作物免受感染。 / 我們在研究中從不同的植物來源成功純化出各種防禦蛋白,包括:小芋頭塊莖中的血凝素、日本長芋中的凝集素、東北紅豆中的血凝素和抗真菌多肽、棕色芸豆中的凝集素、抗真菌多肽和胰蛋白酶抑製劑,玉豆一號中的凝集素以及小斑豆中的胰蛋白酶抑製劑。小芋頭血凝素被發現能誘導脾細胞的有絲分裂反應。日本長芋凝集素和東北紅豆血凝素被發現能對一些腫瘤細胞株(如乳腺癌MCF7細胞及鼻咽癌CNE2細胞)發揮抗增殖的作用。棕色芸豆凝集素能誘導脾臟細胞的有絲分裂反應以及抑制腫瘤細胞株(如乳腺癌MCF7細胞、肝癌HepG2及鼻咽癌CNE1和 CNE2細胞)的生長,而棕色芸豆抗真菌蛋白能抑制數種病原真菌物種的生長。研究這些防禦蛋白的生物活性有助找出其潛在應用價值,如藥用前景。 / Infection from pathogens is one of the major health hazards in higher organisms including plants. To defend against harmful invaders, most plants produce a variety of defense proteins including lectins, protease inhibitors, antifungal proteins, ribonucleases and ribosome-inactivating proteins. They may be present in different organs of the plants, such as leaves, roots, seeds and tubers. Some of the plant defense proteins were found to exhibit a variety of biological activities such as anti-tumor activity, anti-bacterial activity and anti-viral activity that act against various plant pathogens and also some human pathogens. Therefore, some plant defense proteins may have potential for therapeutic applications in human diseases, or protecting the crops from infections. / This study involved purification of defense proteins from different plant sources. The proteins that were successfully isolated included a hemagglutinin from small taro tubers, a lectin from Japanese yam tubers, a lectin and an antifungal peptide from northeast red beans, a lectin, an antifungal peptide and a trypsin inhibitor from brown kidney beans, a lectin from French bean cultivar no. 1 and a trypsin inhibitor from mini pinto beans. The small taro hemagglutinin was found to induce mitogenic response in splenocytes. The Japanese yam lectin and northeast red bean hemagglutinin were found to exert anti-proliferative activity toward some tumor cell lines including MCF7 and CNE2 cells. The brown kidney bean lectin induced a mitogenic response from murine splenocytes as well as inhibited the growth of tumor cell lines including MCF7, HepG2, CNE1 and CNE2 cells, while the brown kidney bean antifungal protein inhibited the growth of several pathogenic fungal species including M. arachidicola, S. turcica and B. maydis. Studying the biological activities of these defense proteins helps to find out their potential applications like therapeutic uses. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chan, Yau Sang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves i-xvii). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i-ii / 論文摘要 --- p.iii / Acknowledgements --- p.iv / List of Publications --- p.v / Table of Contents --- p.vi-vii / List of Figures --- p.viii-ix / List of Tables --- p.x / List of Abbreviations --- p.xi / Chapter Chapter 1 --- Introduction on plant defense proteins / Chapter 1.1 --- General introduction to plant defense proteins --- p.1-2 / Chapter 1.2 --- An overview on lectins --- p.3-18 / Chapter 1.2.1 --- History of lectins --- p.3-6 / Chapter 1.2.2 --- Classification of lectins --- p.7-11 / Chapter 1.2.3 --- Biological activities of lectins --- p.12-16 / Chapter 1.2.4 --- Applications of plant lectins --- p.16-18 / Chapter 1.3 --- An overview on defensins --- p.18-25 / Chapter 1.3.1 --- Types of defensins --- p.18-21 / Chapter 1.3.2 --- Mechanism of anti-microbial activity of defensins --- p.22-23 / Chapter 1.3.3 --- Application of defensins --- p.23-25 / Chapter 1.4 --- An overview on trypsin inhibitors --- p.25-38 / Chapter 1.4.1 --- Serpins --- p.26-28 / Chapter 1.4.2 --- Kunitz-type protease inhibitors --- p.29-31 / Chapter 1.4.3 --- Bowman-Birk protease inhibitors --- p.32-34 / Chapter 1.4.4 --- Physiological functions of protease inhibitors --- p.35-38 / Chapter 1.5 --- Aim of study --- p.38-41 / Chapter Chapter 2 --- Isolation and characterization of a hemagglutinin from small taros and a lectin from yam tubers / Chapter 2.1 --- Introduction --- p.42-45 / Chapter 2.2 --- Materials and Methods --- p.46-55 / Chapter 2.3 --- Results --- p.56-78 / Chapter 2.4 --- Discussion --- p.79-84 / Chapter Chapter 3 --- Isolation and characterization of two defense proteins from seeds of Phaseolus vulgaris cv. “northeast red bean“ / Chapter 3.1 --- Introduction --- p.85-86 / Chapter 3.2 --- Materials and Methods --- p.87-93 / Chapter 3.3 --- Results --- p.93-119 / Chapter 3.4 --- Discussion --- p.120-129 / Chapter Chapter 4 --- Isolation and characterization of three defense proteins from seeds of Phaseolus vulgaris cv. “brown kidney bean“ / Chapter 4.1 --- Introduction --- p.130-131 / Chapter 4.2 --- Materials and Methods --- p.131-136 / Chapter 4.3 --- Results --- p.136-175 / Chapter 4.4 --- Discussion --- p.176-189 / Chapter Chapter 5 --- Isolation and characterization of a lectin from French bean cultivar no. 1 beans and a trypsin inhibitor from mini pinto beans / Chapter 5.1 --- Introduction --- p.190-191 / Chapter 5.2 --- Materials and Methods --- p.191-194 / Chapter 5.3 --- Results --- p.195-212 / Chapter 5.4 --- Discussion --- p.213-221 / Chapter Chapter 6 --- General discussion / Chapter 6.1 --- Summary on purification protocols of the defense proteins in the study --- p.222-228 / Chapter 6.2 --- Chemical properties of the defense proteins in the study --- p.228-232 / Chapter 6.3 --- Biological activities of the defense proteins in the study --- p.232-238 / Chapter 6.4 --- Potential application of these defense proteins and future perspectives --- p.238-242 / References --- p.i-xvi
Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328123 |
Date | January 2012 |
Contributors | Chan, Yau Sang., Chinese University of Hong Kong Graduate School. Division of Biomedical Sciences. |
Source Sets | The Chinese University of Hong Kong |
Language | English, Chinese |
Detected Language | English |
Type | Text, bibliography |
Format | electronic resource, electronic resource, remote, 1 online resource (xii, 250, xvii leaves : ill. (some col.) |
Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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