Distribution of active alpha- and beta-subunits of beta-N-acetylhexosaminidase as a function of leukaemic cell types
Distribution of active alpha- and beta-subunits of beta-N-acetylhexosaminidase as a function of leukaemic cell types
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DOI：
10.1016/s0304-4165(96)00116-x
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发表时间：
1997-04-17
影响因子：
3
通讯作者：
Orlacchio, A
中科院分区：
文献类型：
--
作者：
Martino, S;Emiliani, C;Orlacchio, A
β-N-乙酰氨基己糖苷酶同工酶，以及在新鲜白血病细胞和建立的白血病细胞系的代表性系列中形成该酶的α-和β-亚基的分布，是通过使用DEAE-纤维素层析和用被α和β亚基水解的荧光底物4-甲基伞形酮基-β-N-乙酰氨基葡糖苷测定的组合获得的，和4-甲基伞形酮基-β-N-乙酰氨基葡糖苷-6-SO 4，其仅被含有α-亚基的己糖胺酶同工酶水解。氨基己糖苷酶S（α-α-二聚体）的存在，在我们调查的所有白血病细胞群中发现，但在正常人类细胞中没有。因此，这种同工酶的存在可以被认为是白血病细胞的额外标志物。普遍存在氨基己糖苷酶A和A样中间形式（α β结构）是髓源性白血病细胞的特征，而大量氨基己糖苷酶B和B样中间形式（β β结构）是淋巴源性白血病细胞的一致属性。原始细胞中β亚基的过度表达可能与其未分化状态有关。这些变化的同工酶的氨基己糖苷酶可能证明信息的各种变化的白血病细胞的生物学，可以从染色体的改变，蛋白水解加工和糖基化的变化。
beta-N-Acetylhexosaminidase isoenzymes, and the distribution of the alpha- and beta-subunits forming the enzyme in a representative series of fresh leukaemic cells and in established leukaemic cell lines, were obtained by using a combination of DEAE-cellulose chromatography and assay with the fluorogenic substrates 4-methylumbelliferyl-beta-N-acetylglucsaminide hydrolyzed by both alpha and beta subunits, and 4-methylumbelliferyl-beta-N-acetylglucosaminide-6-SO4 hydrolyzed only by hexosaminidase isoenzymes containing alpha-subunits. The presence of hexosaminidase S (the alpha alpha dimer), was found in all the leukaemic cell populations we surveyed, but not in normal human cells. The presence of this isoenzyme can therefore be considered as an additional marker of leukaemic cells. A prevalence of hexosaminidase A and A-like intermediate forms (alpha beta structure), characterize leukaemic cells of myeloid origin, whereas greater amounts of hexosaminidase B and B-like intermediate forms (beta beta structure), were consistent attributes of leukaemic cells of lymphoid origin. An over-expression of beta-subunits in blasts might be related to their undifferentiated status. These changes in the isoenzymes of hexosaminidase may prove informative about a variety of changes in the biology of leukaemic cells that could range from chromosomal alterations to changes in the proteolytic processing and glycosylation.