Design of novel polymer adsorbents for selective removal of DNA

为了从用作药物的细胞产物溶液中去除核酸，制备了活化的聚（γ-甲硫氨酸-谷氨酸）（PMLG-NH_2）颗粒和交联的聚（乙烯亚胺）（PH）球形颗粒。粒径为44 ~ 105 μm的颗粒被用作吸附剂。使用分批法测定DNA和细胞产物对吸附剂的吸附。在pH 7.0和离子强度μ = 0.05条件下，氨基含量为3.5 meq/g的PMLG-NH_2吸附剂对核酸（鲑鱼精巢DNA）的吸附活性随氨基含量和孔径（多糖分子量排阻）的增大而增大<lim>，随着孔径从2 × 10^3增大到2 × 10^5，DNA与PMLG-NH_2吸附剂的表观解离常数（Kd）从8.2 × <-13>10^mol/l（M）减小到2.0 × <-13>10^M。而对牛血清白蛋白（BSA）的吸附活性则随粒径的增大而增大<lim>。 关于我们 es，但随着缓冲液离子强度的增加而降低。结果表明，当分子量<lim>为2 × 10^3，氨基含量为3.5 meq/ml时，在pH 7.0，离子强度μ = 0.2时，PMLG-NH_2对蛋白质等含DNA样品的DNA有较好的吸附效果。<-8><-10>在生理条件下（离子强度μ = 0.2，pH 7.0），DNA与PEI吸附剂之间的Kd随PEI比例从50增加到90单位摩尔%而从8.5 × 10^M下降到9.5 × 10^M。另一方面，BSA的吸附活性也随着吸附剂的PEI比率从70单位摩尔%或更高而增加，但随着缓冲液的离子强度的增加而急剧下降。当PEI比小于70 unit-mol%时，γ-球蛋白的吸附活性随PEI比的降低而增加。结果，当PEI比率为80单位摩尔%的PEI吸附剂用作吸附剂时，它们仅在离子强度μ = 0.2和pH 7.0下从各种蛋白质溶液中选择性地去除DNA。该吸附剂可使各蛋白质溶液中DNA的浓度降至10 ng/ ml以下，蛋白质回收率均在97%以上。少

To remove nucleic acids from a solution of a cell product used as a drug, animated poly(γ-metbyl L-glutamate) (PMLG-NH_2) particles and cross-linked poly(ethyleneimine) (PH) spherical particles were prepared. The particles, which had diameters of 44 to 105 μm were used as adsorbents. The adsorption of DNA and cell products to the adsorbents were determined using a batchwise method. The adsorbing activity for nucleic acid (purified DNA from salmon spermary) increased with increase in either the amino-group content or pore-size (molecular mass exclusion of polysaccharide, M_<lim>) of the adsorbent.The apparent dissociation constant (K_d) between the DNA and the PMLG-NH_2 adsorbent (amino-group content: 3.5 meq/g) decreased from 8.2 × 10^<-13> mol/l (M) to 2.0 × 10^<-13> M with increase in pore size from 2 × 10^3 to 2 × 10^5, at pH 7.0 and an ionic strength of μ = 0.05. On the other hand, the adsorbing activity of bovine serum albumin (BSA) increased with increasing M_<lim> of the particl … More es, but decreased with increasing ionic strength of the buffer. As a result, when M_<lim> was 2 × 10^3 and amino-group content was 3.5 meq/ml, the PMLG-NH_2 removed DNA from various DNA-containing samples, such as protein solutions, at pH 7.0 and ionic strength (μ) of 0.2.The K_d between the DNA and the PEI adsorbent decreased from 8.5 × 10^<-8> to 9.5 × 10^<-10> M with an increase in PEI ratio from 50 to 90 unit-mol% under physiological conditions (ionic strength of μ = 0.2, pH 7.0). On the other hand, the adsorbing activity of BSA also increased with increasing PEI ratio of the adsorbent from 70 unit-mol% or higher, but sharply decreased with increasing buffer's ionic strength. The adsorbing activity of γ-globulin increased with decreasing PEI ratio to 70 unit-mol% or lower. As a result, when the PEI adsorbent, having a PEI ratio of 80 unit-mol%, were used as the adsorbent, they only selectively removed DNA from various protein solutions at an ionic strength of μ = 0.2 and a pH of 7.0. The adsorbent decreased the concentration of DNA in each protein solution to less than 10 ng/ ml, and the recovery rate of protein was more 97% in all cases. Less