A matched set of fluorescent dyes is provided, wherein each dye of the set is capable of covalent attachment to a protein and wherein each of the dyes has a molecular structure and a charge that is matched one with the other, such that relative electrophoretic mobility of a protein labelled with one dye of the set is the same as the electrophoretic mobility of the protein labelled with a different dye of the set. The matched set comprises at least two different fluorescent dyes of formula:
wherein n is 1, 2, or 3; Z
1
and Z
2
independently represent the carbon atoms necessary to complete a phenyl or naphthyl ring system; one of groups R
1
and R
2
is a target bonding group; remaining group R
1
or R
2
is selected from —(CH
2
)
4
—W or —(CH
2
)
r
—H; group R
3
is hydrogen, except when either R
1
or R
2
is —(CH
2
)
r
—H, in which case R
3
is W; and W is selected from sulphonic acid and sulphonate. The invention also provides a method for saturation labelling of a protein with a fluorescent dye so as to label all available target amino acid, suitably cysteine, residues in the protein, thereby giving a single population of labelled protein molecules.
提供了一组匹配的荧光
染料,其中该组
染料中的每种
染料都能与蛋白质共价连接,每种
染料的分子结构和电荷彼此匹配,从而使用该组
染料中的一种
染料标记的蛋白质的相对电泳迁移率与用该组
染料中的另一种
染料标记的蛋白质的电泳迁移率相同。匹配的
染料组至少包括两种不同的荧光
染料,其式如下
其中 n 为 1、2 或 3; Z
1
和 Z
2
分别代表完成苯基或
萘基环状系统所需的碳原子;基团 R
1
和 R
2
中的一个是靶键基团;其余基团 R
1
或 R
2
选自-(CH
2
)
4
-W或-(CH
2
)
r
-H;基团 R
3
是氢,除非当 R
1
或 R
2
是-(CH
2
)
r
-H,在这种情况下,R
3
是 W;W 选自
磺酸和
磺酸盐。本发明还提供了一种用荧光
染料对蛋白质进行饱和标记的方法,以标记蛋白质中所有可用的目标
氨基酸残基,最好是半胱
氨酸残基,从而得到单一的标记蛋白质分子群。