首页|Site-specific immobilization of papain on DDI-modified polystyrene beads for the oligo(gamma-ethyl-L-glutamate) synthesis

Site-specific immobilization of papain on DDI-modified polystyrene beads for the oligo(gamma-ethyl-L-glutamate) synthesis

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  • NSTL
  • Elsevier
In this paper, a reusable heterogeneous catalyst of papain was prepared and used to catalyze the polymerization for oligo-glutamate. In silico, the 9,9-bis(2,3-epoxypropyl) fluorenyl group (DDI) carried on polystyrene beads (PS-PEG-DDI) showed site-specific binding for sites which are far away the active site of papain. The immobilization of papain on PS-PEG-DDI reached the optimal value of 126 +/- 2.5 mg/g beads and 1726.2 +/- 34 U/g beads at the papain/beads ratio of 1:5 in phosphate buffer (pH 8.0, 200 mM) at 45 degrees C for 4 h. The storage stability, pH stability, thermal stability, solvent tolerance and resistance to metal ions of papain were enhanced by the immobilization. The oligomerization of L-glutamic acid diethyl ester hydrochloride via PS-PEG-DDI immobilized papain in phosphate buffer (pH 8, 200 mM) at 45 degrees C demonstrated the yield of oligo(gamma-ethyl-L-glutamate) reached 78.6 +/- 1.2% under the conditions of 2 U/ml of papain, 60 mg/ml L-glutamic acid diethyl ester hydrochloride for 4 h. The immobilization increased the yield by about 40%. The analysis by mass spectrometry (MS) and H-1 NMR showed an average degree of polymerization (DPavg) of product was approximately 7-8, identical to that produced using free papain. The biocatalytic activity of the PS-PEG-DDI immobilized papain remained stable after 5 repeated uses, all giving a yield of over 70%. The reduced activation energy of the reaction catalyzed by the PS-PEG-DDI immobilized papain suggests a more favorable active conformation was probably achieved following immobilization.

Site-specific immobilizationPapain99-Bis(23-epoxypropyl) fluorenyl groupIn silicoOligo(gamma-ethyl-L-glutamate)PROTEASE-CATALYZED OLIGOMERIZATIONCOVALENT IMMOBILIZATIONENZYME IMMOBILIZATIONPEPTIDE-SYNTHESISALPHA-AMYLASEETHYL-ESTERSSTABILIZATIONPOLYMERIZATIONPERFORMANCESTABILITY

Wang, Feng、Yu, Lu、Li, Chao、Xia, Xiaofeng、Zhang, Fuming、Linhardt, Robert J.

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Jiangnan Univ

Rensselaer Polytech Inst

2022

10.1016/j.apcata.2021.118472

Applied Catalysis

Applied Catalysis

ISSN：0926-860X
年,卷(期)：2022.630
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