The invention provides methods to prepare protein conjugates from proteins having at least two cysteines. In one embodiment, a protein with a disulfide linkage is reduced to provide two free cysteines for reaction with a 1,3-dihaloacetone or similar reactant, linking the sulfur atoms of the two cysteines together. The ketone inserted between the sulfur atoms is then used to form a Schiff base to an aminated payload molecule, thus conjugating the protein to a payload. In another embodiment, two cysteine residues are tied together by reaction with a 1,3-dihaloacetone or similar reactant. The linkage between the sulfur atoms in each case holds the protein or peptide in a constrained conformation, while also providing a convenient place for attaching a payload with good specificity and efficiency.
该发明提供了一种从至少含有两个半胱
氨酸的蛋白质制备蛋白质共轭物的方法。在一个实施例中,将含有二
硫键的蛋白质还原,以提供两个自由的半胱
氨酸,用于与1,3-二卤代
丙酮或类似试剂发生反应,将两个半胱
氨酸的
硫原子连接在一起。然后,插入在
硫原子之间的
酮基被用来与
氨基负载分子形成席夫碱,从而将蛋白质与负载结合起来。在另一个实施例中,通过与1,3-二卤代
丙酮或类似试剂发生反应,将两个半胱
氨酸残基连接在一起。在每种情况下,
硫原子之间的连接使蛋白质或肽以受限构象存在,同时还提供了一个方便的位置,用于连接具有良好特异性和效率的负载。