금속 친화성 액 이상분계 시스템에서 단백질의 분배 향상 = Enhanced Partitioning of Proteins in Metal-Affinity Aqueous Two-Phase Systems

국문 초록 (Abstract)

금속 친화성 액 이상분계 시스템에서 단백질 분배는 pH, 단백질 표면에 존재하는 histidine수, metallated PEG 리간드의 농도 및 분배계수에 의해 영향을 받는다. 금속 친화성이 있는 단백질 분배를 향상시키기 위하여, 기존의 금속 친화성 리간드로 사용되어온 Cu(II)IDA-PEG5,000보다 분배계수가 높은 CU(II)_2IDA_2-PEG20,000을 합성하여 PEG/dextran 이상분계 시스테에서 새로운 금속 친화성 리간드로 사용하였다. 단백질 분배 실험은 horse cytochrome c, S. cerevisiae cytochrome c, horse myoglobin, sheep myoglobin을 모델 시스템으로 하여 수행하였으며, 실험 결과 Cu(II)IDA-PEG5,000보다 Cu(II)_2IDA_2-PEG20,000을 사용하였을 경우에 향상된 단백질 분배계수를 얻을 수 있었다.

다국어 초록 (Multilingual Abstract)

In metal-affinity aqueous two-phase systems, protein partitioning is affected by a variety of parameters such as pH, the number of surface-accessible histidines, and the amount and partition coefficient of metallated polyethylene glycol(PEG) ligand. To enhance partitioning of proteins with surface-accessible histidines, we have synthesized and used a (Cu(II)-iminodiacetic acid)_2-PEG20,000(Cu(II)_2IDA_2-PEG20,000) as well as Cu(II)IDA-PEG5,000 as an affinity ligand. The partition coefficient of Cu(II)_2IDA_2-PEG20,000 in a PEG5,000/dextran two-phase system was 30.1, which corresponded to a 3.8-fold increase over that of Cu(II)IDA-PEG5,000. The partitioning experiments were performed on four proteins, horse cytochrome c, S. cerevisiae cytochrome c, horse myoglobin, and sheep myoglobin. Partitioning of proteins which convey surface-accessible histidines was enhanced dramatically by the addition of Cu(II)_2IDA_2-PEG20,000 ligand. These results demonstrate that enhanced partitioning of metal-binding proteins in an aqueous two-phase system can be achieved by using an appropriate metallacted PEG ligand.