Besides, the spacer carbon chain length of the tetrameric quaternary ammonium ion also displays important influence on the performance of the system.
另外，季铵离子头基之间的连接链长度对体系的性能也有重要的影响。
2
Streptavidin is a 53,000 dalton tetrameric protein purified from the bacterium Streptomyces avidinii (3). Each subunit binds to biotin with extremely high affinity.