申请人:Molecular Probes, Inc.
公开号:US05208148A1
公开(公告)日:1993-05-04
The claimed invention relates to a substrate for evaluating glycosidic enzymes comprising a fluorescein derivative of the general formula: ##STR1## wherein GlyX is a carbohydrate bonded to fluorescein by a glycosidic linkage; Y, which may be the same as GlyX or different, is an alkyl ether, an ester, or a glycosidically linked carbohydrate; R is a lipophilic residue containing from 1 to 21 carbon atoms; and L links the R residue to fluorescein. A preferred embodiment of the invention is a non-fluorescent substrate specifically hydrolyzable by a glycosidase inside a cell to yield, after greater than about 2 minutes, a fluorescent detection product excitable at between about 460 nm and 550 nm and with fluorescence observable at an emission wavelength longer than the excitation wavelength, which fluorescent detection product is retained inside a viable cell more than about 2 hours at greater than about 15.degree. C. and which is non-toxic to the cell. A further embodiment of the invention is a method for evaluating a glycosidic enzyme in living plant or animal cells whether the enzyme is present endogenously; present as a result of manipulation of the cell's genome, or added to the cell exogenously, such as by covalently binding the enzyme to a protein to form an enzyme-protein complex that enters the cell.
所述发明涉及一种用于评估糖苷酶的底物,其中包括一种荧光素衍生物,其通式为:##STR1## 其中GlyX是通过糖苷键与荧光素结合的碳水化合物;Y可能与GlyX相同或不同,是烷基醚,酯或糖苷化碳水化合物;R是含有1至21个碳原子的亲脂性残基;L将R残基与荧光素连接起来。该发明的一种优选实施例是一种非荧光底物,特别是可被细胞内的糖苷酶水解,在大约2分钟后产生可在460 nm至550 nm之间激发的荧光检测产物,并且其荧光在发射波长上可观察到比激发波长更长,该荧光检测产物在大约15°C以上的活细胞内保持超过2小时,并且对细胞无毒性。该发明的另一实施例是一种方法,用于评估生物体内或动物细胞中的糖苷酶,无论该酶是否内源性存在;由于细胞基因组的操纵而存在;或通过将酶共价结合到蛋白质上形成酶-蛋白质复合物并进入细胞而外源性添加到细胞中。