Psychrophilic Enzymes: From Folding to Function and Biotechnology

Feller, Georges

doi:10.1155/2013/512840

Cited by 252 publications

(238 citation statements)

References 305 publications

(349 reference statements)

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“…The cumulative effect on thermodynamic activation parameters, originating from the differences in the sequence between cold-and warm-active trypsin, seems to be fully captured by restraining the protein surface and offers a novel approach to understanding thermodynamic parameters. It should also be pointed out here that the amino acids of the active site are fully conserved in salmon and bovine trypsin, as has been found in other comparative studies of cold-and warm-active enzymes (20). From an evolutionary perspective this also makes sense, because mutations in the active site are likely to have a large negative effect on the catalytic efficiency.…”

Section: Discussionsupporting

confidence: 56%

Enzyme surface rigidity tunes the temperature dependence of catalytic rates

Isaksen

Åqvist

Brandsdal

2016

Proc. Natl. Acad. Sci. U.S.A.

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The structural origin of enzyme adaptation to low temperature, allowing efficient catalysis of chemical reactions even near the freezing point of water, remains a fundamental puzzle in biocatalysis. A remarkable universal fingerprint shared by all cold-active enzymes is a reduction of the activation enthalpy accompanied by a more negative entropy, which alleviates the exponential decrease in chemical reaction rates caused by lowering of the temperature. Herein, we explore the role of protein surface mobility in determining this enthalpy-entropy balance. The effects of modifying surface rigidity in cold-and warmactive trypsins are demonstrated here by calculation of high-precision Arrhenius plots and thermodynamic activation parameters for the peptide hydrolysis reaction, using extensive computer simulations. The protein surface flexibility is systematically varied by applying positional restraints, causing the remarkable effect of turning the coldactive trypsin into a variant with mesophilic characteristics without changing the amino acid sequence. Furthermore, we show that just restraining a key surface loop causes the same effect as a point mutation in that loop between the cold-and warm-active trypsin. Importantly, changes in the activation enthalpy-entropy balance of up to 10 kcal/mol are almost perfectly balanced at room temperature, whereas they yield significantly higher rates at low temperatures for the cold-adapted enzyme.enzyme cold adaptation | thermodynamic activation parameters | empirical valence bond | temperature dependence | molecular dynamics C old-adapted enzymes are able to catalyze their reactions with chemical rates comparable to and often exceeding those of their warm-active counterparts, and they are a remarkable example of how evolution can tune the biophysical properties of enzymes. Despite major efforts in the last few decades, the structural mechanisms responsible for low-temperature activity still remain largely unknown. A key problem with lowering the temperature is the exponential decrease in enzyme reaction rates, which according to transition state theory is given byHere, k rxn is the reaction rate, T the temperature, κ is a transmission coefficient, k and h are Boltzmann's and Planck's constants, respectively, and ΔG ‡ is the free energy of activation. Decreasing the temperature from 37°C to 0°C typically results in a 20-to 250-fold reduction of the activity of a mesophilic enzyme (1). Clearly, survival at low temperatures requires that both enzyme kinetics and protein stability are adapted accordingly.A remarkable and universal feature of reactions catalyzed by cold-adapted enzymes is a lower enthalpy and a more negative entropy of activation compared with thermophilic orthologs (1-3). This enthalpy-entropy phenomenon, as indicated in Fig. 1A, coincides with the fact that psychrophilic enzymes have a reduced thermostability, and thus melt at lower temperatures than their mesophilic counterparts. It is evident from Eq. 1 that a lower activation enthalpy makes the rate less tempe...

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Section: Discussionsupporting

confidence: 56%

Enzyme surface rigidity tunes the temperature dependence of catalytic rates

Isaksen

Åqvist

Brandsdal

2016

Proc. Natl. Acad. Sci. U.S.A.

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“…A few of them stabilizes at intramolecular salt bridges and a many of them occupy the surface and may confer the conformational flexibility (Alquati et al 2002;Siddiqui & Cavicchioli 2006;Feller 2013). Additional structural features responsible for cold adaption are high content and aggregation of glycine residues (for local mobility), low content of ion pairs and weak charge-dipole interactions in α helices (Georlette et al 2004;Gomes & Steiner 2004).…”

Section: Structural Features and Cold Adaptionmentioning

confidence: 99%

Cold active lipases – an update

Kavitha

2016

Frontiers in Life Science

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Cold active lipases (CLPs) are gaining importance nowadays as they are increasingly used in fine chemical synthesis, bioremediation, food processing and as detergent additive. These enzymes exhibit high catalytic activity at low temperatures and flexibility to act at low water medium. Since they are active at low temperatures consume less energy and also stabilize fragile compounds in the reaction medium. CLPs are commonly obtained from psychrophilic microorganisms which thrive in cold habitats. Compared to mesophilic and thermophilic lipases, only a few CLPs were studied and industrially exploited so far. CLPs (C. antarctica lipase-A and C. antarctica lipase-B) from Candida antarctica isolated from Antarctic region are the well studied and industrially employed, and many are being followed up. This review updates the CLPs reported recently and the industrial applications of CLPs. ARTICLE HISTORY

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“…The enzymatic activity is strongly dependent on temperature. The specific activity of the psychrophilic enzymes is very high at low temperatures, but never higher than that of the mesophilic enzyme at 37°C (Feller 2013). The weak stability of the psychrophilic enzymes and their inactivation at moderate temperatures could explain the slopes of the activities recorded to assays at 50°C.…”

Section: Discussionmentioning

confidence: 91%

Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

Lavín¹,

Átala²,

Gallardo-Cerda³

et al. 2016

Polish Polar Research

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Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta), in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17 ºC) and maximum temperature (20°C) of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C), agarose (50°C) and alginate (30°C) during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

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Psychrophilic Enzymes: From Folding to Function and Biotechnology

Cited by 252 publications

References 305 publications

Enzyme surface rigidity tunes the temperature dependence of catalytic rates

Enzyme surface rigidity tunes the temperature dependence of catalytic rates

Cold active lipases – an update

Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

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