Studies on the enantioselective retention mechanisms of cellobiohydrolase I (CBH I) by covalent modification of the intact and fragmented protein

✍ Scribed by Mikael Hedeland; Hongbin Henriksson; Roland Isaksson; Göran Pettersson

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 200 KB
• Volume: 10
• Category: Article
• ISSN: 0899-0042
• DOI: 10.1002/(sici)1520-636x(1998)10:8<760::aid-chir7>3.0.co;2-6

✦ Synopsis

In order to elucidate the chiral recognition mechanisms of the enzyme cellobiohydrolase I (CBH I), its carboxylic groups were covalently modified. The synthetic modification was carried out either in the presence or absence of cellobiose, which has proven to inhibit the enzymatic activity and if present in the mobile phase impairs enantioselectivity of amino alcohols. Compared to the reference CSP (unmodified CBH-I silica and CBH-I core silica), the synthetically modified phases show differences both in enantioselectivity and retention. The enzymatic differences between the CSPs were also in line with the chromatographic results. The selectivity factors of propranolol are almost unchanged during the reaction periods in the presence of cellobiose, while they decreased rapidly without the inhibitor. In one case, even a slight improvement in enantioselectivity was obtained, indicating that non-stereospecific carboxylic groups were ruled out.