氨基酸序列的特征描述

Characteristic description of amino acid sequences

氨基酸序列的特征描述是指从一条氨基酸序列选取相关的特征信息并用数学方法描述这些信息,使之能正确反映序列与结构或功能之间的关系。在根据氨基酸序列预测蛋白质的结构类或亚细胞位置等问题中,氨基酸序列的特征描述直接影响预测质量;同时比较不同描述方法对预测结果的影响可以帮助我们理解序列与结构或序列与功能之间的关系。本文介绍了几种氨基酸序列的特征描述方法,以FDOD方程作为判别函数,比较了其中几种描述方法对蛋白质结构类预测结果的影响,发现二级结构单纯的全α类和全β类蛋白质对于氨基酸组成比较敏感,而对于混合型蛋白质,即α+β类和α/β类蛋白质,考虑氨基酸残基排列顺序可以显著提高预测结果。

Given an amino acid sequence, what features should be derived from it and how to formulize these features so as to represent the relationship between the sequence and the structure or function of the corresponding protein correctlyβ This is the problem of characteristic description of the amino acid sequence. In the studies of protein structural classes prediction and prediction of protein subcellular location the characteristic description of the amino acid sequences decides the quality of a prediction method. Moreover, comparing different descriptions of the amino acid sequences helps to understand the relationship between the sequences and the structures or functions of proteins. In this paper we summarize several descriptions of amino acid sequence. Taking FOOD function as the discriminant function, some of the descriptions are adopted to predict protein structural classes. By comparing the predictive results it is found that all-aproteins and all-βproteins are sensitive to amino acid composition; however, for the mixed proteins, α + βproteins and α/βproteins, the predictive quality can be improved considerately by taking into account the residue order along the sequences.