Effect of number of poly(His) tags on the adsorption of engineered proteins on immobilized metal affinity chromatography adsorbents

摘要: Abstract The equilibrium adsorption of four homo-oligomeric recombinant proteins containing up to eight poly(histidine) affinity tags on a silica-based Cu(II)-IDA immobilized metal chromatography (IMAC) adsorbent is reported in this study. data are well fitted with the three-parameter Langmuir–Freundlich isotherm model, indicating presence positive cooperativity for these model and degree seems increase number poly(His) tags. This phenomenon also supported by concave-downward curves Scatchard analysis. maximum capacities IMAC proteins, declining from 31.79 nmol/g gel 88 kDa epimerase 21.50 nmol/g 320 kDa racemase, principle affected size molecule, binding strengths, expressed term association constants K increasing 1.47 μM−1 dimeric 50.01 μM−1 octameric dictated Nevertheless, some structure-specific interactions observed among native N-carbamoylase molecules may promote multilayer thus lead much higher capacity, 715 nmol/g lower compounded affinity, 0.42 μM−1. eliminated under denaturing conditions, resulting homogeneous Langmuir model.