背角无齿蚌碱性磷酸酶的功能基团研究

STUDIES OF FRAGILE SITES OF GIANT PANDA ( Ailuropoda Melanoleuca ) CHROMOSOMES INDUCED BY BrdU

在一定条件下，分别采用ＰＭＳＦ，ＤＴＴ，ＰＣＭＢ，ＮＢＳ，ＴＮＢＳ，ＳＵＡＮ，ＢｒＡｃ及ＩＡｃ等化学修饰剂，选择修饰背角无齿蚌碱性磷酸酶的多种氨基酸残基，并测定其酶活力变化．结果表明，ＰＭＳＦ，ＮＢＳ，ＴＮＢＳ，ＳＵＡＮ和ＤＴＴ的修饰能显著抑制酶的活力，而且活力的降低程度与修饰剂的浓度相关．ＢｒＡｃ，ＩＡｃ和ＰＣＭＢ的修饰不表现对酶的抑制作用．初步认为，Ｓｅｒ，Ｌｙｓ和Ｔｒｐ残基是背角无齿蚌碱性磷酸酶的必需功能基团，部分二硫键对保护酶的催化功能也是必需的．

Using cultured lymphocytes of giant panda Ailuropoda melanoleuca as experimental material,the authors researched the fragile sites on the chromosomes induced by BrdU.Combined with banding technique,the authors get the outline of fragile sites′s distribution and appearance frequence on the chromosomes.To different fragile sites,its expression frequence is also different dramatically.Especially,the fragile site at the centromere of chromosome 2 is very sensitive to BrdU,its expression frequence can be as high as 40%.In addition,the mechanism how BrdU inducing fragile sites has been discussed.