Tryptophan and Aliphatic Side Chain of Amino Acids Adsorb onto Aliphatic Ligands through Different Driving Forces

色胺酸及烷基側鏈胺基酸經由不同驅動力吸附至含烷基鏈之吸附基材

劉至一(Chih-I Liu) ； 林伯勳(Po-Hsun Lin) ； 李碧芬(Bi-Fen Lee) ； 阮若屈(Ruoh-Chyu Ruaan)

《Journal of the Chinese Institute of Chemical Engineers》 36卷5期 (2005/09) Pp. 467-473

https://doi.org/10.6967/JCICE.200509.0467

摘要

本文以三種系列之短鏈胜肽來探討其在商用疏水性吸附劑(Octyl-Sepharose)之吸附機制。實驗結果顯示含色胺酸之胜肽，其吸附主要為焓驅動，單一色胺酸殘基對焓之貢獻約-9.4～-11.8 kJ/mol。但我們也發現含烷基側鏈胺基酸之胜肽，其吸附則為熵驅動。此外，我們將烷基側鏈胺基酸插入GWWG中，其結果顯示焓、熵值均較於相同位置插入甘胺酸為高。此一結果更確切指出烷基側鏈胺基酸之疏水性吸附主要為熵驅動。結果也顯示烷基側鏈胺基酸與疏水性吸附劑間之直接作用力是微弱的，色胺酸與疏水性吸附劑間則具有很強的直接作用力。

並列摘要

The hydrophobic adsorption of three series of small peptides on commercial Octyl-Sepharose resins were investigated. The adsorption of tryptophan containing peptides was found to be driven by enthalpy. The enthalpy of adsorption on Octyl-Sepharose per tryptophan residue was approximately -9.4~-11.8 kJ/mol. Meanwhile, it was found that the hydrophobic adsorption of aliphatic amino acids was probably driven by entropy. When we inserted an aliphatic amino acid into a tryptophan containing peptide, both the adsorption enthalpy and entropy increased compared to the adsorption of a peptide inserted along with glycine at the same position. The results suggested that the hydrophobic adsorption of aliphatic amino acids was entropy driven. Apparently, the direct interactions between octyl chains and aliphatic amino acids were weak, but those between octyl chains and tryptophans are particularly strong.

並列關鍵字

Hydrophobic interaction ； Gibbs free energy ； Enthalpy ； Entropy ； Apolar amino acids ； Octyl-Sepharose