Engineered Surface-Immobilized Enzyme that Retains High Levels of Catalytic Activity in Air

Abstract

In the absence of aqueous buffer, most enzymes retain little or no activity; however, "water-free" enzymes would have many diverse applications. Here, we describe the chemically precise immobilization of an enzyme on an engineered surface designed to support catalytic activity in air at ambient humidity. Covalent immobilization of haloalkane dehalogenase on a surface support displaying poly(sorbitol methacrylate) chains resulted in ∼40-fold increase in activity over lyophilized enzyme powders for the gas-phase dehalogenation of 1-bromopropane. The activity of the immobilized enzyme in air approaches 25% of the activity obtained in buffer for the immobilized enzyme. Poly(sorbitol methacrylate) appears to enhance activity by replacing protein-water interactions, thereby preserving the protein structure.

Graphene oxide enabled long-term enzymatic transesterification in an anhydrous gas flux

“…To investigate whether the GO sheets stabilize the CALB structure by preserving water molecules or by directly interacting with the CALB, we applied the thermogravimetric analysis (TGA) to determine the water contents of the lyophilized LGA, CALB and GO, respectively. We determined the mass loss of the bounded water molecules by incubating these materials at 110 °C for 30 min 37 . As shown in Fig.…”

“…Efforts have been made to rationally tailor the stability 33 , activity-pH profiles 34 , substrate affinity 35 , and reaction specificity of enzymes in aqueous phase 36 . A very recent gas-phase example by Badieyan et al 37 suggested that a hydrophilic microenvironment created by polymer network can preserve the activity of enzymes in a water-free condition. Compared with the lyophilized enzyme, they found that haloalkane dehalogenase immobilized on the surface of glass beads displaying poly(sorbitol methacrylate) could result in a 40-fold increase in activity at A w = 0.5.…”

Real-Time observation of protein transport across membranes by femtosecond sum frequency generation vibrational spectroscopy

“…Sum frequency generation vibrational spectroscopy (SFG-VS) has been demonstrated to be a powerful technique for investigating the interfacial structures and interactions at the molecular level . In previous studies, frequency-scanning SFG system has been effectively employed to investigate the static structure of proteins and peptides at different interfaces [4,5,7,8,25]. Despite many progresses, frequency-scanning SFG system takes more than ten minutes to acquire one spectrum.…”

Mechanoenzymatic Transformations in the Absence of Bulk Water: A More Natural Way of Using Enzymes

“…For the most sensitive enzymes, immobilization, encapsulation, or cross‐linking may help preserve activity under mechanical stress. Interestingly, immobilization has been demonstrated to increase the stability of haloalkane dehalogenase specifically under gas‐phase conditions . Further studies looking at improving protein stability in the context of mechanoenzymology are warranted to improve yields and facilitate enzyme recycling.…”

“…Interestingly,i mmobilization has been demonstrated to increaset he stability of haloalkaned ehalogenase specifically under gas-phase conditions. [160] Further studies lookinga ti mproving protein stabilityi nt he context of mechanoenzymology are warranted to improvey ields and facilitate enzyme recycling. The mechanical forces enabling mechanoenzymatic transformations have so far included batch processes in shakero r planetary mills, and continuous or batch extrusion.…”