Preparation of Keratin-Glycine Metal Complexes and Their Scavenging Activity for Superoxide Anion Radicals

Abstract

To address the problem of limited application of natural SOD, the development of SOD mimic enzymes is of great importance for bioantioxidation. Herein, we report on a new type of biopolymer antioxidant with excellent scavenging activity for O2•-, keratin-glycine metal complexes (FK-GlyM, M = Zn, Cu, Mn, Ni). They are prepared by feather keratin firstly combined with glycine and then metal ions. Using FT-IR, TG, CD, and SEM, the performance of the obtained complexes (FK-GlyM) for scavenging O2•- is analysed and investigated. Importantly, the scavenging activity of FK-GlyCu is excellent in all FK-GlyM, and FK-GlyCu60 has the most excellent anti-O2•- activity in all FK-GlyCux, of which EC50 and degree of simulation were, respectively, up to 4.5×10-3±0.0012 μmol/L and 911.1% compared with nature Cu, Zn-SOD. Finally, its mechanism was also discussed. In summary, this method about the simulation strategies will provide a novel idea for exploiting new-type biocompatible and highly reactive antioxidants.

Multivalent Ions as Reactive Crosslinkers for Biopolymers—A Review

“…Experiments with use of model peptides e.g., poly-l-lysine demonstrated the ability of these molecules to form stable metal complexes [151]. Formation of metal complexes with feather keratin could be obtained with use of glycine metal complexes (e.g., Zn 2+ , Cu 2+ , Mn 2+ , and Ni 2+ ), which exhibits the ability of proteinaceous structures to act as solid ligands for bivalent metal ions [152] ( Figure 22). Complex formation of metal ions with wool also was demonstrated with sorption experiments and polarographic analysis of the equilibrium concentrations using different metal ions (e.g., Cu 2+ , Pb 2+ , and Cd 2+ ) and different processed wool samples [153].…”

“…The formation of Cu 2+ complexes with silk fibroin was found to be dependent on the structure of the fibroin, e.g., Figure 22. Formation of glycine metal complexes and metal complex crosslinks with feather keratin (M = Zn 2+ , Cu 2+ , Mn 2+ , and Ni 2+ ) (based on [152]).…”

“…25, x FOR PEER REVIEW 25 of Formation of glycine metal complexes and metal complex crosslinks with feather keratin (M = Zn 2+ , Cu 2+ , Mn 2+ , and Ni 2+ ) (based on[152]). …”

Increased Recovery of Gold Thiosulfate Alkaline Solutions by Adding Thiol Groups in the Porous Structure of Activated Carbon

“…The thiol groups, especially sodium thioglycolate, can reduce disulfide bonds, later, these can be re-oxidized by insertion of transition metal ions. This property is used to obtain nanoparticles of keratin metal complexes [ 40 ]. In this sense, the thiol group of the thioglycolate anion could break the disulfide bond (S-S) of the gold thiosulfate complex.…”