초록

본 연구에서는 초고온 미생물인 Aquifex pyrophilus의 단백질 분해효소인 Aqualysin의 응용 및 의료산업에 쓰이는 효소인 Superoxide dismutase(SOD)에 대한 효소의 열역학적 특성 및 구조적 연구를 심화시키며 동시에 DNA 치료(repair)에 관련된 FEN-1과 thioredoxin등의 구조적, 열역학적 연구를 함께 추진한다.

Abstract ▼

The purpose of this study (Study on the structure and characteristics of proteins from hyperthermophiles) is to determine the 3-D structure of thermostable proteins and the structural information of the proteins from hyperthermophiles will provide valuable informations about the factors which stabil

The purpose of this study (Study on the structure and characteristics of proteins from hyperthermophiles) is to determine the 3-D structure of thermostable proteins and the structural information of the proteins from hyperthermophiles will provide valuable informations about the factors which stabilize protein structure. These information will be used for designing more robust industrial or therapeutic enzymes. We cloned whole genes for several thermostable proteins which were important in metabolism or protein processing pathway. They were serine-type protease, superoxide dismutase(SOD), FEN-1 and thioredoxin. The proteins from these genes were expressed and the 3-D structure of superoxide dismutase(SOD), FEN-1 and thioredoxin have been determined by X-ray crystallography. We designed two mutants of Superoxide Dismutase (SOD) and they providee valuable insight to identify amino acid residues essential for the thermostability of the SOD from Aquifex pyrophilus (Ap SOD). The results have clearly shown the general significance of hydrogen bonds and ion-pair network in the thermostability of proteins. FEN-1 contains two unusual features; a long, flexible loop which recognizes the substate DNA and an active sith with different ligands-metal coordination. We speculate that these differences may result in the different role of each enzyme in DNA metabolism as well as their substrate specificity. Based on the NMR structure of thioredoxin, we could suggest that a new way to stabilize the protein, which is the hydrophobic interaction of the side chain with the neighboring residues at the surface. In addition, these interactions induce the increasing of unfolding enthalpy and are distinctive to the other protein. For the future study, we will further analyze the 3-D structure of several proteins from hyperthermophiles and study the mechanism of protein stabilization. The obtained information from these hyperthermophilic proteins could be used to protein engineering for biotechnological application.

목차 Contents

• 제 1 장 서론...9
• 제 2 장 국내외 기술개발 현황...10
• 제 3 장 연구개발수행내용 및 결과...11
• 제1절 초고온 미생물의 내열성 분해효소의 특성 분석...11
• 제2절 변이체를 통한 초고온성 Superoxide dismutase의 열안정성 요인 연구...28
• 제3절 Methanococcus jannaschii의 FEN-1 단백질의 구조연구...38
• 제4절 Methanococcus jannaschii의 thioredoxin에 대한 열역학적 특성 및 구조분석...44
• 제 4 장 연구개발목표 달성도 및 대외기여도...63
• 제 5 장 연구개발결과의 활용계획...64
• 제 6 장 참고문헌...65