title: Synthesis of a novel chitosan-based Ce(IV) complex with proteolytic activity in vitro toward edible biological proteins.
abstract: The occurrence of enzymatic activities is attributed to proper spatial organization of functional groups from first principles. A novel chitosan-based Ce(IV) complex (CC[Ce(IV)]), an artificial metalloproteinase, was synthesized by attaching cyclen, Ce(IV), and chlorophyll-Cu(II) to a chitosan-based matrix. The enzymatic hydrolytic efficiency (HE) and the procedure of catalyzing myoglobin (Mb) by CC[Ce(IV)] in vitro were investigated using spectrophotometry, electrophoresis, and liquid chromatography. The results showed that the HE of Mb was up to 60% at 60°C within 24h, displaying a catalytic proficiency. The pseudo-first-order kinetic constant (kobs) for CC[Ce(IV)] treatment within 24h was 3.85×10(-2)h(-1), higher than that for α-chymotrypsin treatment, which was 2.63×10(-2)h(-1). Moreover, the peptide bond derived from Asp-Phe/Phe-Asp in Mb could be specifically cleaved by CC[Ce(IV)], which could simulate the functionality of α-chymotrypsin. This work provides an experimental basis for potential utilization of the chitosan-based Ce(IV) complexes in the food industry.
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Bingjie
authors.initials: B
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Zihui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Xianghong
authors.initials: X
authors.lastname: Meng
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China. Electronic address: wangdf@ouc.edu.cn.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D040761:Biomimetic Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D002417:Cattle; D002586:Cesium / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D048271:Chitosan / Q000737:chemistry*; D002918:Chymotrypsin / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009211:Myoglobin / Q000737:chemistry / Q000378:metabolism; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D059748:Proteolysis
chemical_list: D009211:Myoglobin; D009942:Organometallic Compounds; D002586:Cesium; D048271:Chitosan; D002918:Chymotrypsin; C117608:alpha-chymotrypsin
keywords: Acetic acid (PubChem CID: 176); Acetonitrile (PubChem CID: 6342); Artificial metalloproteinases; Ce(IV); Ceric(IV) ammonium nitrate (PubChem CID: 56841022); Chitosan; Cleavage; Coomassie brilliant blue G250 (PubChem CID: 6333920); Cyclen; Epichlorohydrin (PubChem CID: 7835); Formaldehyde (PubChem CID: 712); Glutaraldehyde (PubChem CID: 3485); Ninhydrin (PubChem CID: 10236); Peptide bonds; Span 80 (PubChem CID: 5385498); Trichloroacetic acid (PubChem CID: 6421)