純化與定性人類胎盤的甘露糖六磷酸接受體

Abstract

利用β-galactosidase sepharose親和管柱，β-glucosidase sepharose親和管柱及膠體過濾管柱（F.P.L.C./SuperoseTM 12），可自人類胎盤中純化出甘露糖六磷酸接受體（mannose 6-phosphate receptor），其分子量為46 KDa。 在pH 6.5的分析緩衝液中，最適合甘露糖六磷酸接受體和β-galactosidase結合，pH值高於7或低於5都不適合甘露糖六磷酸接受體的結合作用。 二價金屬錳離子有助於甘露糖六磷酸接受體和β-galactosidase 的結合，但是二價鋅離子與鎂離子則沒有顯著的影響。

The cation dependent mannose 6-phosphate receptor has been purified from the human placenta by using combination of β-galactosidase sepharose affinity chromatography, β-glucosidase sepharose affinity chromatography and F.P.L.C. SuperoseTM 12 gel filtration chromatography. The molecular weight of the purified mannose 6-phosphate receptor is about 25 KDa. In the ligand binding assay, receptor bound to ligand in the absence or presence of divalent cation with similar efficency. Divalent cations were not required for ligand binding, but the binding of β-galactosidase with the receptor was improved by 10mM Mn2+.The receptor exhibited optimum binding of β-galactosidase at pH 6.5.