Department of Chemical and Biological Science, NSF I/UCRC for Biocatalysis and Bioprocessing of Macromolecules, Polytechnic Institute of NYU, Six Metrotech Center, Brooklyn, New York 11201, USA.
Biomacromolecules. 2010 Aug 9;11(8):2152-60. doi: 10.1021/bm100516x.
Enzymatic synthesis of oligopeptides from l-phenylalanine ethyl ester hydrochloride (l-Phe-Et.HCl) and other l-form hydrophobic amino acid ester hydrochlorides in water miscible organic cosolvents was studied. Different proteases, water miscible cosolvents, and effect of different ratios of water miscible cosolvents for protease-catalyzed oligo-phenylalanine [oligo(l-Phe)] were compared. The importance of the use of water miscible cosolvents in transforming reactions from heterogeneous to homogeneous conditions as a potent medium engineering tool for protease-catalyzed oligopeptide synthesis is highlighted. For example, at 0.125 M l-Phe-Et.HCl, 20% (v/v) methanol, 18.6 mg/mL bromelain, in phosphate buffer (0.25M, pH 8), 40 degrees C, for 3 h, oligo(l-Phe) precipitated from the solution to yield 45 +/- 5%, in contrast, in the absence of cosolvent oligo(l-Phe) yield of 29 +/- 5% was obtained. The following reaction conditions were optimized for bromelain catalyzed oligo(l-Phe) synthesis: pH, temperature, substrate, enzyme, and cosolvent concentrations. DP(avg) and chain length distribution in the product peptides were investigated by (1)H NMR and MALDI-TOF.
在水混溶性有机溶剂中，用酶从 l-苯丙氨酸乙酯盐酸盐（l-Phe-Et.HCl）和其他 l 型疏水性氨基酸酯盐酸盐合成低聚肽的研究。比较了不同的蛋白酶、水混溶性溶剂以及水混溶性溶剂对蛋白酶催化的寡聚苯丙氨酸[寡聚（l-Phe）]的不同比例的影响。强调了使用水混溶性溶剂将转化反应从多相条件转化为均相条件作为一种有效的介质工程工具在蛋白酶催化的寡肽合成中的重要性。例如，在 0.125 M l-Phe-Et.HCl、20%（v/v）甲醇、18.6 mg/mL 菠萝蛋白酶、磷酸盐缓冲液（0.25 M，pH 8）、40°C、3 h 的条件下，寡聚（l-Phe）从溶液中沉淀出来，产率为 45 +/- 5%，而在没有溶剂的情况下，寡聚（l-Phe）的产率为 29 +/- 5%。优化了菠萝蛋白酶催化寡聚（l-Phe）合成的反应条件：pH 值、温度、底物、酶和溶剂浓度。通过（1）H NMR 和 MALDI-TOF 研究了产物肽中的 DP(avg)和链长分布。
