title: CAL-B catalyzed regioselective bulk polymerization of l-aspartic acid diethyl ester to α-linked polypeptides.
abstract: This paper reports that the bulk polymerization of l-aspartic acid diethyl ester catalyzed by immobilized CAL-B at 80 °C for 24 h gives primarily (∼95%) α-linked poly(l-aspartate) in 70% yield with DPavg= 50 and regioselectivity (α/β) = 94 : 6. Plots of log{[M]0/[M]t} vs. time and DPavgvs. conversion indicate that this polymerization proceeds in a controlled manner by a chain-growth mechanism up to 90% conversion. Thereafter, competition occurs between chain growth and step mechanisms.
authors.affiliation: Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute (RPI), 4005B Biotechnology Building, 110 Eighth Street, Troy, New York 12180, USA. grossr@rpi.edu.
authors.forename: Filbert
authors.initials: F
authors.lastname: Totsingan
authors.affiliation: Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute (RPI), 4005B Biotechnology Building, 110 Eighth Street, Troy, New York 12180, USA. grossr@rpi.edu.
authors.forename: Robert
authors.initials: R
authors.lastname: Centore
authors.affiliation: Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute (RPI), 4005B Biotechnology Building, 110 Eighth Street, Troy, New York 12180, USA. grossr@rpi.edu.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Gross