Li Sipeng, Ding Zhaoyang, Liu Jifu, Cao Xuejun
State Key Laboratory of Bioreactor Engineering, Department of Bioengineering, East China University of Science and Technology, Shanghai, 200237, China.
Appl Biochem Biotechnol. 2017 Dec;183(4):1254-1264. doi: 10.1007/s12010-017-2495-3. Epub 2017 May 20.
ε-Poly-L-lysine (ε-PL) is a natural preservative for food processing industry. A thermo-responsive polymer, attached with Cu or Ni, was prepared for metal-chelate affinity precipitation for purification of ε-PL. The low critical solution temperatures (LCSTs) of these polymers were close to the room temperature (31.0-35.0 °C). The optimal adsorption conditions were as follows: pH 4.0, 0 mol/L NaCl, ligand density 75.00 μmol/g, and 120 min. The ligand Cu showed a stronger affinity interaction with ε-PL and the highest adsorption amount reached 251.93 mg/g polymer. The elution recovery of ε-PL could be 98.42% with 0.50 mol/L imidazole (pH = 8.0) as the eluent. The method could purify ε-PL from fermentation broth and the final product was proved as electrophoretic pure by SDS-PAGE. Moreover, these affinity polymers could be recycled after the purification of ε-PL and the recoveries were above 95.00%. Graphical Abstract Scheme for affinity precipitation of ε-PL.
ε-聚-L-赖氨酸（ε-PL）是食品加工业中的一种天然防腐剂。制备了一种与铜或镍结合的热响应聚合物，用于金属螯合亲和沉淀法纯化ε-PL。这些聚合物的低临界溶液温度（LCST）接近室温（31.0 - 35.0°C）。最佳吸附条件如下：pH 4.0、0 mol/L氯化钠、配体密度75.00 μmol/g以及120分钟。配体铜与ε-PL表现出更强的亲和相互作用，最高吸附量达到251.93 mg/g聚合物。以0.50 mol/L咪唑（pH = 8.0）作为洗脱剂时，ε-PL的洗脱回收率可达98.42%。该方法可从发酵液中纯化ε-PL，通过SDS-PAGE证明最终产物为电泳纯。此外，这些亲和聚合物在纯化ε-PL后可循环使用，回收率高于95.00%。ε-PL亲和沉淀示意图
