Utilizing Avidity To Improve Antifreeze Protein Activity: A Type III Antifreeze Protein Trimer Exhibits Increased Thermal Hysteresis Activity
| Autor: | Nolan B. Holland, Özge Can |
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| Rok vydání: | 2013 |
| Předmět: |
Models
Molecular Protein Folding Trimer Protein Engineering Biochemistry Substrate Specificity symbols.namesake Cryoprotective Agents Antifreeze protein Antifreeze Proteins Animals Avidity Volume concentration Cryopreservation Eels Thermal hysteresis Chromatography Chemistry Langmuir adsorption model Recombinant Proteins Protein Structure Tertiary Freezing point Cold Temperature symbols Biophysics Protein Multimerization Protein Binding Protein adsorption |
| Zdroj: | Biochemistry. 52:8745-8752 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi401345b |
| Popis: | Antifreeze proteins (AFPs) are ice growth inhibitors that allow the survival of several species living at temperatures colder than the freezing point of their bodily fluids. AFP activity is commonly defined in terms of thermal hysteresis, which is the difference observed for the solution freezing and melting temperatures. Increasing the thermal hysteresis activity of these proteins, particularly at low concentrations, is of great interest because of their wide range of potential applications. In this study, we have designed and expressed one-, two-, and three-domain antifreeze proteins to improve thermal hysteresis activity through increased binding avidity. The three-domain type III AFP yielded significantly greater activity than the one- and two-domain proteins, reaching a thermal hysteresis of1.6 °C at a concentration of1 mM. To elucidate the basis of this increase, the data were fit to a multidomain protein adsorption model based on the classical Langmuir isotherm. Fits of the data to the modified isotherms yield values for the equilibrium binding constants for the adsorption of AFP to ice and indicate that protein surface coverage is proportional to thermal hysteresis activity. |
| Databáze: | OpenAIRE |
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