2361-98-0Relevant academic research and scientific papers
Solubilisation of α-chymotrypsin by hydrophobic ion pairing in fluorous systems and supercritical carbon dioxide and demonstration of efficient enzyme recycling
Benaissi, Karima,Poliakoff, Martyn,Thomas, Neil R.
, p. 54 - 59 (2010)
Hydrophobic ion-pairing (HIP) with the fluorinated surfactant KDP 4606 (KDP) was used to extract the protein α-chymotrypsin (CMT) into perfluoromethylcyclohexane (PFMC). The diameter of the solubilised CMT-KDP complexes formed in PFMC was determined by dynamic light scattering (DLS) to be 25 nm which suggested the formation of a protein aggregate containing ～100 protein molecules surrounded by KDP 4606 surfactant molecules per particle. The catalytic activity of the protease CMT either solubilised by HIP or as the suspended native enzyme has been investigated in both a fluorous biphasic system (FBS) and a supercritical carbon dioxide (scCO2) batch reactor. Transesterification of N-acetyl-l-phenylalanine ethyl ester (APEE) with n-butanol or rac-2-butanol was catalysed by the protease in the FBS hexane-PFMC or scCO2 at 40 °C. Under comparable conditions, the amount of transesterification of the solubilised protease-surfactant (CMT-KDP) complex in PFMC (6-10%) was shown to be significantly higher than that of the suspended protease (1-3%) in either hexane-PFMC or scCO2. This suggested the formation of a catalytically active CMT-KDP aggregate in PFMC. The CMT-KDP complex which is retained in the fluorous phase on cooling the solution was successfully reused over four cycles with no loss of activity.
Enhancing the catalytic efficiency of subtilisin for transesterification by dual bioimprinting
Mukherjee, Joyeeta,Gupta, Munishwar N.
, p. 4397 - 4401 (2015/06/22)
Bioimprinting is a technique in which an aqueous solution of a protein molecule along with the imprint molecule is dried to remove bulk water. Subtilisin was dissolved in an aqueous buffer with a substrate analog and precipitated with the substrate alcoho
Asymmetric chemoenzymatic synthesis of N-acetyl-α-amino esters based on lipase-catalyzed kinetic resolutions through interesterification reactions
Da Silva, Marcos Reinaldo,De Mattos, Marcos Carlos,De Oliveira, Maria Da Concei??o Ferreira,De Lemos, Telma Leda Gomes,Ricardo, Nágila Maria Pontes Silva,De Gonzalo, Gonzalo,Lavandera, Iván,Gotor-Fernández, Vicente,Gotor, Vicente
, p. 2264 - 2271 (2014/03/21)
Several phenylalanine analogs have been synthesized through a four-step route starting from easily available ethyl acetamidocyanoacetate. In a first reaction, and making use of phase transfer catalysts, this compound reacted with several alkyl halides, being benzyltributylammonium chloride identified as the best one for the production of a series of quaternary amino acids in moderate to excellent yields (52-95%). Then, the corresponding N-acetyl-phenylalanine methyl and allyl ester derivatives were obtained through acidic hydrolysis, esterification, and N-acetylation. Rhizomucor miehei lipase was found as a versatile enzyme for the resolution of these amino esters, finding the best results through interesterification reactions with butyl butyrate in acetonitrile. A great influence in the stereoselectivity was found depending on the chemical structure of the compound, achieving for the non- or para-substituted in the phenyl ring excellent stereoselectivities, being moderate for the meta-nitro derivative, while the ortho-nitro amino ester did not react.
Homogeneous enzymatic reactions in ionic liquids with poly(ethylene glycol)-modified subtilisin
Nakashima, Kazunori,Maruyama, Tatsuo,Kamiya, Noriho,Goto, Masahiro
, p. 3462 - 3467 (2008/09/18)
Subtilisin Carlsberg was covalently modified with comb-shaped poly(ethylene glycol) (PM13). PM13-modified subtilisin (PM 13-Sub) was readily solubilized in three different ionic liquids (ILs), i.e., [Emim][Tf2N], [C2OC1mim][Tf 2N] and [C2OHmim][Tf2N]. Analysis of homogeneous enzymatic reactions in the ILs revealed that PM13-Sub exhibited excellent catalytic performance while the native enzyme suspended in ILs showed no activity. Hydrophobicity of ILs slightly affected enzyme activity, and the relatively hydrophobic IL [Emim][Tf2N] was the preferred medium for enzymatic reactions, similar to enzymatic reactions in conventional organic solvents. Enzyme activity was much higher in [Emim][Tf2N] than in conventional organic solvents, and excellent activity was associated with unique properties of ILs such as hydrophobicity and high polarity. Furthermore, PM13-Sub showed good stability in [Emim][Tf 2N], and maintained 80% of its initial activity after 60 h. The Royal Society of Chemistry 2006.
