Purification and properties of two forms of human α-L-fucosidase
學年 68
學期 1
出版(發表)日期 1980-01-01
作品名稱 Purification and properties of two forms of human α-L-fucosidase
著者 Chien, Su-fang; Dawson, Glyn
單位 淡江大學化學學系
出版者 Amsterdam: Elsevier BV
著錄名稱、卷期、頁數 Biochimica Et Biophysica Acta. General Subjects 614(2), pp.476-488
摘要 High (100 000) and low (50 000) molecular weight forms of α-L-fucosidase (α-fucosidase I and II) were purified to apparent homogeneity from human spleen, liver, brain and kidney on the basis of differential affinity for ε-amino-caproyl fucosamine-agarose bead columns. α-Fucosidase I (the 'bound' form) consisted of two 50 000 dalton monomers; however, both forms can aggregate to tetramer and hexamer forms. Most previous studies on α-fucosidase have been carried out on this form of human α-fucosidase although the bound and unbound forms of the enzyme were present in equal amounts in human spleen. The bound (100 000) form is a sialoglycoprotein whereas the unbound (50 000) form, is a neutral mannose-rich glycoprotein. Other differences with respect to amino acid composition, pH optimum, electrophoretic mobility, K(m), thermal stability, and natural substrate specificities were observed. All preparations hydrolysed 4-methylumbelliferyl-α-L-fucoside, fucosyllactose, and lacto-N-fucopentaose I, but the unbound fraction (α-fucosidase II) preferentially hydrolysed lacto-N-fucopentaose II. The unbound (mannose-rich) α-fucosidase II was taken up by human skin fibroblasts with higher affinity (5% per 2 h per 2.105 cells) than the bound (sialo-) α-fucosidase I (<1% per 2.105 cells). Uptake was inhibited by other lysosomal hydrolases, fetal calf serum, mannose 6-phosphate and phosphomannans and to a lesser extent by heparins. Our studies suggest that α-fucosidase I is not a simple dimer of α-fucosidase II and represents a less-biologically active form of the enzyme.
語言 en
ISSN 0304-4165
期刊性質 國外
通訊作者 Dawson, Glyn
國別 NLD
出版型式 ,紙本

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/61701 )