CAJ | 학술논문

酚氧化酶原PPO是昆虫免疫的关键酶,本文从牛物信息学角度对亚洲玉米螟Ostrinia furnacalis Guenee幼虫PPO进行分析,为进一步研究其高级结构与功能的关系提供理论依据.利用我们已提交到GenBank的数据,采用在线分析及MEGA4和RasMol软件对亚洲玉米螟酚氧化酶原(Of-PPO)的核苷酸和氨基酸序列、系统发生关系和蛋白质三级结构进行分析.结果表明:Of-PPO全长cDNA序列有2 686 bp,包含一个2 079 bp的开放阅读框,其推导的693个氨基酸序列中包含6个组氨酸残基构成的2个铜离子结合位点,以及保守的硫羟酸酯区域.Of-PPO属于PP为O2类群,其N端不含信号肽,无跨膜结构域区域,无糖基化位点,44个磷酸化位点均匀分布于整个多肽链中,有2段序列可能形成卷曲螺旋,有5个区域的氨基酸具较强疏水性,其二级结构中α-螺旋占22.54%,随机卷曲占56.79%.同源建模显示其三级结构为"α/β型"中的"滚筒结构",存在一个明显的空位,可能与该酶催化活性有关.本文可为Of-PPO的实验研究和应用开发提供有价值的信息.
분양화매원PPO시곤충면역적관건매,본문종우물신식학각도대아주옥미명Ostrinia furnacalis Guenee유충PPO진행분석,위진일보연구기고급결구여공능적관계제공이론의거.이용아문이제교도GenBank적수거,채용재선분석급MEGA4화RasMol연건대아주옥미명분양화매원(Of-PPO)적핵감산화안기산서렬、계통발생관계화단백질삼급결구진행분석.결과표명:Of-PPO전장cDNA서렬유2 686 bp,포함일개2 079 bp적개방열독광,기추도적693개안기산서렬중포함6개조안산잔기구성적2개동리자결합위점,이급보수적류간산지구역.Of-PPO속우PP위O2류군,기N단불함신호태,무과막결구역구역,무당기화위점,44개린산화위점균균분포우정개다태련중,유2단서렬가능형성권곡라선,유5개구역적안기산구교강소수성,기이급결구중α-라선점22.54%,수궤권곡점56.79%.동원건모현시기삼급결구위"α/β형"중적"곤통결구",존재일개명현적공위,가능여해매최화활성유관.본문가위Of-PPO적실험연구화응용개발제공유개치적신식.
Prophenoloxidase (PPO) is a key enzyme of insect immunity. In this study, the nucleotide sequence and deduced amino acid sequence of PPO cloned from the larvae of Ostrinia furnacalis were analyzed and predicted by the tools of bioinformatics in the following aspects: the composition of nucleotide sequences and amino acid sequences, signal peptide, trans-membrane topological structure, hydrophobicity or hydrophilicity, secondary structure, tertiary structure, etc. The results showed that the full-length cDNA of 0. furnacalis PPO (Of-PPO) consisted of 2 686 bp, containing an open reading frame (ORF) of 2 079 bp. Based on the 693 deduced amino acid sequences of Of-PPO, a putative thiolester site and two distinct copper binding regions were found, which included six histidine residues. Of-PPO belongs to the PPO2 group, and there is no signal peptide in the N-terminal region of the polypeptide chain. No possible transmembrane protein model was found. There was no O-glycosylation site in Of-PPO predicted with DictyoGlyc. Forty-four phosphorylation sites were predicted in the whole peptide by NetPhos 2.0 Server. Two regions of Of-PPO could form coil structures, and five regions were found with significant hydrophobic characteristics. The proportions of α-helix and random coil in the secondary structure of Of-PPO were 22.54% and 56.79% , respectively. The comparative modeling method was used to calculate the tertiary structure of Of-PPO, and the result showed that it was the "roller" shape, which belongs to the α/β type. The catalytic activity may relate with a large vacant space in Of-PPO structure analyzed by the RasMol software. This study may provide valuable information for further research on Of-PPO.