Immobilization of proline-specific endoprotease on nonporous silica nanoparticles functionalized with amino group
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Enzyme immobilization is believed to provide an excellent base for increasing environmental tolerance of enzyme and considerable period of time. In this work, a kind of nonporous silica nanoparticles functionalized with amino group was synthesized to immobilize proline-specific endoprotease (PSEP). PSEP is known to specifically cleave peptides (or esters) at the carboxyl side of proline, thus can prevent the formation of haze and prolong the shelf life of beer. After immobilization, the environmental tolerance (temperature and pH, respectively) was obviously improved, and the immobilized enzyme can retain above 90 % of its original activity after 6 uses. Moreover, the immobilized enzyme can effectively prevent the formation of chill-haze using fresh beer fermentation liquid.
KeywordsEnzyme immobilization Proline-specific endoprotease Enzymatic activity Beer Chill-haze
This work is supported by the National Natural Science Foundation of China (Nos. 21433001, 21273260), Applied Basic Research Foundation of Qingdao City (No. 14-2-4-21-jch), and Shandong Provincial Natural Science Foundation for Distinguished Young Scholar, China (No. JQ201305).
- 1.Nadzeyka A, Altenhofen U, Zahn H (1979) The significance of beer proteins in relationship to cold-break and age-related haze formation. Brauwissenschaft, Germany, FRGoogle Scholar
- 5.Siebert KJ, Lynn PY (1997) Mechanisms of beer colloidal stabilization. J Am Soc Brew Chem 55:73–78Google Scholar
- 9.Kotlikova B, Jelinek L, Karabin M, Dostalek P (2013) Precursors and formation of colloidal haze in beer. Chem Listy 107:362–368Google Scholar
- 10.Leiper KA, Miedl M (2008) Colloidal stability of beer. Academic Press, Burlington, MAGoogle Scholar
- 14.Finn J, Surrel A, Robinson L, Sheehy M, Stewart D, Eglinton J, Evans E (2007) Investigation of the impact of proline specific endoproteinase on malt haze-active and foam-active proteins. In: Australian Barley Technical Symposium, 26–29 August 2007, Fremantle, Western AustraliaGoogle Scholar
- 25.Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
- 26.Lopez M, Edens L (2004) Method for the prevention or reduction of haze in beverages. US patent 20040115306 A1Google Scholar