葡聚糖与 NASI 辐射接枝共聚及与 BSA 的偶合反应

STUDY ON RADIATION GRAFTING OF NASI ON SEPHADEX AND CONJUGATION OF THE COPOLYMER WITH BSA

用辐射接枝技术将Ｎ－丙烯酰氧基丁二酰亚胺（ＮＡＳＩ）接枝在ＳｅｐｈａｄｅｘＧ７５和ＳｅｐｈａｄｅｘＧ５０上。接枝率随剂量增加而增大，１０ｋＧｙ后趋于平缓，剂量率对接枝率无明显影响。两种接枝物分别与牛血清白蛋白（ＢＳＡ）进行偶合反应。在０．２ｍｏｌ／Ｌ、ｐＨ＝７．４的磷酸盐缓冲液中３８℃下恒温缓慢搅拌６ｈ可达偶合平衡。每克ＢＳＡ可偶合ＳｅｐｈａｄｅｘＧ７５－ＮＡＳＩ３．０×１０－４ｍｍｏｌ。ＳｅｐｈａｄｅｘＧ５０－ＮＡＳＩ由于Ｇ５０型孔隙度过小，ＢＳＡ无法渗入，偶合反应难以进行。但ＳｅｐｈａｄｅｘＧ５０－ＮＳＡＩ却可与带－ＮＨ２、小分子量的中性红发生偶合反应，偶合摩尔比接近１∶１。

N acryloxysuccinimide(NASI) with a function ester group is grafted on Sephadex G75 and Sephadex G50 separately by radiation technology. The radiation grafting conditions including absorbed dose,dose rate,monomer concentration in solvent are investigated. The conjugation reactions between the grafted copolymers Sephadex G75 NASI,and bovine serum albumin(BSA) or Sephadex G50 NASI and bovine serum albumin (BSA)are followed. The experiment results show that the conjugate of Sephadex G75 NASI with larger holes and BSA ( M r=6.6×10 4) is obtained successfully,however,the Sephadex G50 with small holes can be only conjugated with neutral red ( M r=2.58×10 2)。