植物合成多種發病機理相關蛋白以對抗病原體的侵襲。植物發病機理相關蛋白包括：核糖核酸酶；抗真菌蛋白；凝集素；胰蛋白酶抑制因子等。這些發病機理相關蛋白具有抗病毒，抗細菌，抗真菌，免疫調節及抗腫瘤等活性。從六種植物中提純了七個發病機理相關蛋白，包括三個凝集素，一個核糖核酸酶，兩個種抗真菌蛋白及一個胰蛋白酶抑制因子。 / 從西洋參須中提純了新的核糖核酸酶。核糖核酸酶分子量為26kDa，具有特异N末端氨基酸序列。此核糖核酸酶在 pH5 及 60℃ 條件下活性最高。它能抑制腫瘤細胞分裂及抑制人類後天免疫力缺乏症候群病毒逆轉錄酶活性。 / 從粉色菜豆及日本大花豆中提純了兩種凝集素。它們由兩個分子量為32kDa的亞基構成雙倍體。他們的活性穩定于0-60℃及3-12 pH。粉色菜豆凝集素的特异性糖基為木糖，日本大花豆凝集素的特异性糖基為半乳糖。從太子參中提純的凝集素分子量為33kDa，其活性穩定于0-60℃及2-5 pH。 這三種凝集素都具有抑制腫瘤細胞分裂及抑制人類後天免疫力缺乏症候群病毒逆轉錄酶活性。 / 提純的胰蛋白酶抑制因子分子量為21kDa。具有高耐熱及耐酸鹼性并表現出抑制腫瘤細胞分裂及抑制人類後天免疫力缺乏症候群病毒逆轉錄酶活性。從豇豆中提純的抗真菌肽分子量為5447Da，具有類防御素N末端氨基酸序列。 / Plants produce a diversity of proteins with antipathogenic activities. These proteins comprise among others, (i) ribonucleases, (ii) antifungal proteins, (iii) lectins and (iv) trypsin inhibitor with antiviral, antifungal and anticancer activities. The aim of this project was to isolate antipathogenic plant proteins including a ribonuclease from American ginseng branch roots, a trypsin inhibitor from rambutan seeds, defensin-like antifungal peptides from borlotti beans and king pole beans, and lectins from borlotti beans, Japanese large pinto beans and Pseudostellaria heterophylla. / The isolated 26-kDa ginseng branch root ribonuclease was monomeric with a novel N-terminal amino acid sequence. It exhibited maximal robonucleolytic activity toward yeast tRNA at pH 5 and 60℃. It inhibited proliferation of MCF7 human breast cancer cells and HepG2 human hepatoma cells. It also inhibited the activity of HIV-1 reverse transcriptase. / Both borlotti bean lectin and Japanese large pinto bean lectin were dimeric with a subunit molecular mass of 32-kDa. They were stable from 0℃ to 60℃ and from pH 3 to pH 12. Borlotti bean lectin was xylose-specific whereas Japanse large pinto bean lectin was galactose-specific. The 33-kDa Pseudostellaria heterophylla lectin could not be inhibited by the simple sugars tested. It was stable from 0℃ to 60℃ and from pH 2 to 5. All three isolated lectins suppressed proliferation of MCF7 and HepG2 cells and inhibited HIV-1 reverse transcriptase. / The isolated 21-kDa rambutan trypsin inhibitor has relatively high pH stability and thermostability, and exhibited HIV-1 reverse transcriptase inhibitory activity and antiproliferative activity toward a variety of tumor cells. The isolated 5447-Da king pole bean defensin-like peptide inhibited fungal growth. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhao, Yuan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 202-222). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iv / Declaration --- p.v / Abbreviations --- p.vi / Table of Contents --- p.vii / List of Tables --- p.x / List of Figures --- p.xii / Chapter Chapter 1 --- Overview of Plant Defense-related Protein --- p.1 / Chapter 1.1 --- Overview of Lectins and hemagglutinins --- p.4 / Chapter 1.1.1 --- History and definition of lectins and hemagglutinins --- p.4 / Chapter 1.1.2 --- Occurrence and distribution of plant lectins --- p.6 / Chapter 1.1.3 --- Classification of lectins --- p.7 / Chapter 1.1.3.1 --- Classification of lectins on the basis of overall structure of lectin subunits --- p.7 / Chapter 1.1.3.2 --- Classification of lectins based on binding specificty to carbohydrates --- p.11 / Chapter 1.1.3.3 --- Classification of lectins according to families --- p.12 / Chapter 1.1.3.3.1 --- Legume lectins --- p.12 / Chapter 1.1.3.3.2 --- Monocot mannose-binding lectins --- p.13 / Chapter 1.1.3.3.3 --- Other lectins --- p.14 / Chapter 1.1.4 --- Defensive role of plant lectins --- p.15 / Chapter 1.1.5 --- Applications of plant lectins --- p.18 / Chapter 1.1.5.1 --- The antibacterial activity --- p.18 / Chapter 1.1.5.2 --- Anti-insect activity --- p.19 / Chapter 1.1.5.3 --- Antifungal activity --- p.21 / Chapter 1.1.5.4 --- The antiviral activity --- p.22 / Chapter 1.1.5.5 --- Lectin affinity chromatography --- p.23 / Chapter 1.1.5.6 --- Lectin microarray --- p.23 / Chapter 1.2 --- Overview of Ribonucleases --- p.26 / Chapter 1.2.1 --- History and definition of Ribonucleases --- p.26 / Chapter 1.2.2 --- Classification of Ribonucleases --- p.27 / Chapter 1.2.2.1 --- T1 Ribonucleases family --- p.27 / Chapter 1.2.2.2 --- RNase T2 family --- p.28 / Chapter 1.2.3 --- Biological activities of plant ribonucleases --- p.28 / Chapter 1.2.3.1 --- Phosphate remobilization --- p.28 / Chapter 1.2.3.2 --- Senescence --- p.29 / Chapter 1.2.3.3 --- Programmed cell death --- p.30 / Chapter 1.2.3.4 --- Plant defense --- p.31 / Chapter 1.2.3.5 --- RNA processing and decay --- p.32 / Chapter 1.2.3.6 --- Antitumor activities --- p.33 / Chapter 1.3 --- Other plant pathogen-related proteins --- p.34 / Chapter 1.3.1 --- Overview of chitinase --- p.34 / Chapter 1.3.1.1 --- Classification of chitinases --- p.35 / Chapter 1.3.1.2 --- Biological properties of chitinases --- p.38 / Chapter 1.3.2 --- Overview of plant ribosome-inactivating proteins (RIPs) --- p.41 / Chapter 1.3.2.1 --- Classification of RIPs --- p.42 / Chapter 1.3.2.2 --- Roles of RIPs in plants --- p.44 / Chapter 1.3.2.3 --- Possible application of RIPs --- p.46 / Chapter 1.3.3 --- Overview of thaumatin-like proteins (TLPs) --- p.50 / Chapter 1.3.3.1 --- Occurrence of TLPs --- p.51 / Chapter 1.3.3.2 --- Biological properties of TLPs --- p.52 / Chapter 1.4 --- Aim of this study --- p.54 / Chapter Chapter 2 --- Isolation of a lectin and an antifungal protein from Phaseolus vulgaris cv. Borlotti beans / Chapter 2.1 --- Introduction --- p.55 / Chapter 2.2 --- Materials and Methods --- p.55 / Chapter 2.3 --- Results --- p.64 / Chapter 2.4 --- Discussion --- p.79 / Chapter Chapter 3 --- Isolation of a lectin from Pinto beans (Phaseolus vulgaris pinto bean) / Chapter 3.1 --- Introduction --- p.82 / Chapter 3.2 --- Materials and Methods --- p.83 / Chapter 3.3 --- Results --- p.87 / Chapter 3.4 --- Discussion --- p.103 / Chapter Chapter 4 --- Isolation of a lectin from Pseudostellaria hetorophylla roots / Chapter 4.1 --- Introduction --- p.105 / Chapter 4.2 --- Materials and Methods --- p.107 / Chapter 4.3 --- Results --- p.110 / Chapter 4.4 --- Discussion --- p.122 / Chapter Chapter 5 --- Isolation of a ribonuclease from branch roots of American ginseng (Panax quinquefolium) / Chapter 5.1 --- Introduction --- p.124 / Chapter 5.2 --- Materials and Methods --- p.126 / Chapter 5.3 --- Results --- p.129 / Chapter 5.4 --- Discussion --- p.142 / Chapter Chapter 6 --- Isolation of a trypsin inhibitor in rambutan (Nephelium lappaceum L) seeds / Chapter 6.1 --- Introduction --- p.144 / Chapter 6.2 --- Materials and Methods --- p.147 / Chapter 6.3 --- Results --- p.152 / Chapter 6.4 --- Discussion --- p.163 / Chapter Chapter 7 --- Isoation of a defensin-like antifungal peptide from Phaseolus vulgaris cv. 'King Pole Bean' / Chapter 7.1 --- Introduction --- p.168 / Chapter 7.2 --- Materials and Methods --- p.170 / Chapter 7.3 --- Results --- p.173 / Chapter 7.4 --- Discussion --- p.181 / Chapter Chapter 8 --- Overall discussion --- p.183 / References --- p.186
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_327956 |
| Date | January 2012 |
| Contributors | Zhao, Yuan, 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 (222 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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