【作者】 陈红；

【导师】 王丽萍； 孙黎；

【作者基本信息】 吉林大学 ， 生物工程， 2006， 硕士

【摘要】 过氧化物酶对多种由于自由基损伤而引的疾病的预防和治疗有着重要意义,但由于天然过氧化物酶作为抗氧化药物的种种缺点,用模拟酶的办法来制备具有药用价值的过氧化物酶的模拟物成为了新的研究方向。本文以亚血红素为筛选靶目标,通过噬菌体表面展示肽库筛选出一系列的与亚血红素特异性结合的短肽配基。通过对筛选所得肽片段的氨基酸排列顺序分析,发现了与亚血红素高亲和性有关的氨基酸序列。以得到的序列为基础,经过比较分析,设计了以亚血红素为辅基的抗坏血酸过氧化物酶肽类模拟物,采用Fmoc固相合成法,对设计的肽配体进行了合成,并用LC/MS/MS来对合成的结果进行鉴定,最后研究了合成过氧化物模拟酶活性,实验结果证实合成的过氧化物模拟酶具有很好的活性,具有良好的开发前景。更多还原

【Abstract】 Objection: Peroxidases, which exist in the animals, plants and aerobicmicroorganism, cooperate with other antioxidants to balance the metabolizationof free radicals. In despite of the significance of the peroxidases in the preventionand therapy of the diseases caused by the free radicals, the disadvantages of thenatural peroxidases make it necessary to design and synthesize effective enzymemimics. According to the structure of the enzyme mimics, they could beclassified as simple organic compounds, peptide mimics and protein mimics.Compared to the simple organic compounds, the peptide mimics have theadvantages of low toxicity, high activity and easy synthesis. At the same time,compared with the protein mimics, the peptide mimics have the low molecularweight and high stability. Also the modern technology makes it possible tosynthesize peptide of any sequences.Methods:In this thesis, the phage displaypeptide library was used to screen the small peptide ligand of deuterohemin, andthen the peptide mimic of peroxidases, which use the hemin as the prostheticgroup, was carried out. Because of the low solubility of the deuterohemin, theDeuterohemin-His-Peptide-6 (Dh-AHTVEK) was taken as the screening target.In the mean time, according to the peptide sequence of the DhHP-6, a peptidewas synthesized in the manual way in order to reduce the effect of theintroduction of the peptide to the deuterohemin. After three rounds of screening,individual clones were isolated and sequenced, and a series of small peptideligands specifical to the deuterohemin were obtained. One sequence with highoccurrence frequency has the conserved domain His/Trp/Arg of natural ascorbateperoxidase. From result of the sequence alignment in the database, this smallpeptide sequence is homologous to many catalase, but no uniform sequence existsin the database. This indicates that the putative peptide mimic has the potential ofbecoming a new mimic of peroxidase. On the basis of the data and informationobtained from the experiment, several deuterohemin-His-peptides were designed.In the mimics, the deuterohemin take the place of the hemin whose alkenyls areeasiliy oxidized by the peroxide, which reduces its stability to the peroxide. Thenone mimic of peroxidase, Dh-β -Ala-Phe-His-Trp-Lys-Pro-Tyr-Arg wassynthesized.Conclusions: the mimic of peroxidase was was measured, and have arelative high enzyme activity.更多还原