The primary structure of a protein is the sequence of α-amino-acid residues along its peptide chain, linked by covalent peptide bonds. It is the most basic level of protein structure and is determined by the gene that encodes the protein. The primary structure dictates how the chain will fold into its higher-order secondary, tertiary, and quaternary structures.

蛋白质的一级结构是其肽链上由共价肽键连接的 α-氨基酸残基的排列顺序。它是蛋白质结构最基本的层次,由编码该蛋白质的基因决定。一级结构决定了肽链将如何折叠成更高层次的二级、三级和四级结构。