本文選題：多肽類藥物 + 體外穩(wěn)定性��； 參考：《吉林大學》2014年碩士論文

【摘要】：多肽類藥物在當今醫(yī)藥市場占有非常重要的地位，在治療如糖尿病，腫瘤，癌癥，疫苗，精神性疾病等方面發(fā)揮重大作用。多肽類藥物具有活性高，良好的特異性及靶向性，代謝產(chǎn)物主要為氨基酸、毒副作用小、不易造成積累性中毒，，與傳統(tǒng)藥物相比，成本更低，滲透性更強。但其自身固有的缺點也限制其發(fā)展，穩(wěn)定性差，容易被各種酶解，降解速度快，體內半衰期短，口服利用度低，需頻繁注射給藥，加重了患者身心、經(jīng)濟的負擔。在過去的幾十年里，研究人員已經(jīng)運用大量策略來增加多肽對肽酶的抵抗性，如化學修飾、定點突變、延長肽鏈、引入非天然氨基酸、自組裝修飾、通過二硫鍵環(huán)化等。通過對多肽進行修飾或改造，來提高多肽類藥物的穩(wěn)定性，是當前研究的熱門課題。 血紅素是由原卟啉和鐵離子所形成的配合物，參與多種生理生化反應，具有重要的生理功能。本實驗室根據(jù)設計合成了一個以血紅素為輔基的過氧化物酶：次血紅素六肽（Deuterohemin-AlaHisThrValGluLys，DhHP-6），具有很高的過氧化物酶活性，比活力可達到天然微過氧化物酶MP-11的93％。實驗結果表明，DhHP-6具有延長線蟲壽命，有效清除體內自由基，抗氧化抗衰老，抗心肌氧化損傷等作用，但關于穩(wěn)定性方面的研究較少。 本實驗根據(jù)文獻報道和實驗室前期工作，通過固相肽合成手段將次血紅素基團與四條穩(wěn)定性較差，容易降解的多肽偶聯(lián)，經(jīng)過HPLC分析，MS檢測，分離純化，可以得到純度高達98%以上，物理化學性質穩(wěn)定的次血紅素短肽化合物。結合HPLC，MS分析檢測，對形成的次血紅素短肽化合物在體外血漿，模擬胃液，模擬腸液中的穩(wěn)定性進行研究。實驗結果表明，在體外血漿中，線性肽在1~5min內迅速降解殆盡，次血紅素短肽化合物在與血漿共孵育24h后只降解40%左右，穩(wěn)定性大大提高，半衰期明顯延長；在多肽類藥物非常容易降解的胃腸道模擬液中，次血紅素短肽化合物也有著非常良好的表現(xiàn)，在體外模擬胃液實驗中，次血紅素短肽的半衰期可以達到5min以上；在模擬腸液實驗中，次血紅素短肽的半衰期更是可以達到2h以上，說明次血紅素基團可以有效的提高多肽的穩(wěn)定性，延長半衰期，對肽序列具有一定的保護作用。本實驗有助于研究含有卟啉環(huán)的金屬卟啉多肽與蛋白的設計與應用，為提高多肽類藥物的穩(wěn)定性提供了一條新思路，具有潛在的臨床意義。
[Abstract]:Polypeptide drugs play an important role in the treatment of diabetes, cancer, cancer, vaccines, psychiatric diseases and so on. Polypeptide drugs have high activity, good specificity and targeting, the main metabolites are amino acids, less toxic side effects, not easy to cause accumulative poisoning, compared with traditional drugs, the cost is lower and the permeability is stronger. However, its inherent shortcomings also limit its development, its stability is poor, it is easy to be hydrolyzed by various enzymes, the degradation rate is fast, the body half life is short, the oral utilization is low, and it needs to be injected frequently, which increases the burden of body, mind and economy of the patients. In the past few decades, researchers have used a large number of strategies to increase the resistance of peptides to peptidases, such as chemical modification, site-directed mutation, prolongation of peptide chains, introduction of unnatural amino acids, self-assembly modification, cyclization through disulfide bonds, and so on. It is a hot topic to improve the stability of polypeptide drugs by modifying or modifying peptides. Heme is a complex formed by protoporphyrin and iron ions, which participates in many physiological and biochemical reactions and has important physiological functions. According to the design, a peroxidase, Deuterohemin-Ala-ThrValGluLys-DhHP-6, was synthesized in our laboratory. It has a high peroxidase activity, and its specific activity can reach 93% of that of natural microperoxidase (MP-11). The results showed that DhHP-6 had the effects of prolonging the life of the worm, effectively scavenging free radicals in vivo, anti-aging and anti-oxidative injury of myocardium, but little research on the stability of DhHP-6. In this experiment, according to the literature reports and laboratory work, the heme group was coupled with four peptides with poor stability and easy degradation by solid phase peptide synthesis, and then detected by HPLC and then purified by MS. The subheme short peptide compounds with purity above 98% and stable physical and chemical properties can be obtained. The stability of subheme short peptide compounds in plasma, gastric juice and intestinal fluid was studied by HPLC- MS. The results showed that the linear peptide was degraded rapidly in 1~5min in vitro, the degradation of heme short peptide was only about 40% after incubation with plasma for 24 h, the stability was greatly improved, and the half-life was prolonged. The heme short peptide compounds also have a very good performance in the gastrointestinal mimics which are easily degraded by polypeptide drugs. The half-life of sub-heme short peptides can reach 5min in vitro. In the experiment of simulated intestinal fluid, the half-life of the sub-heme short peptide can reach more than 2 hours, which indicates that the heme group can effectively improve the stability of the peptide, prolong the half-life, and protect the peptide sequence to a certain extent. This study is helpful to study the design and application of metalloporphyrin polypeptides and proteins containing porphyrin ring. It provides a new way to improve the stability of polypeptide drugs and has potential clinical significance.
【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：R91

【參考文獻】

相關期刊論文 前5條

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2 Q

本文編號：1805360