Anion‐regulated binding selectivity of Cr(III) in collagen

Abstract

We present a mechanism for the selectivity of covalent/electrostatic binding of the Cr(III) ion to collagen, mediated by the kosmotropicity of the anions. Although a change in the long-range ordered structure of collagen is observed after covalent binding (Cr(III)-OOC) in the presence of SO 4 2− at pH 4.5, the ν sym (COO −) band remains intense, suggesting a relatively lower propensity for the Cr(III) to bind covalently instead of electrostatically through Cr(H 2 O) 6 3+. Replacing SO 4 2− with Cl − reduces the kosmotropic effect which further favors the electrostatic binding of Cr(III) to collagen. Our findings allow a greater understanding of mechanism-specific metal binding in the collagen molecule. We also report for the first time, surfaceenhanced Raman spectroscopy to analyze binding mechanisms in collagen, suggesting a novel way to study chemical modifications in collagen-based biomaterials.

Zeolites as sustainable alternatives to traditional tanning chemistries

“…When treated with chromium( iii ) sulfate (CS) (COL-Cr), the known changes in peak intensities and positions are confirmed. 35,36 The 3 rd order peak diminishes while the others increase relatively. The peaks also see shifts towards higher q values indicating a smaller D-period between collagen molecules, as shown in Fig.…”

Coadsorbed Species with Halide Ligands on Silver Nanoparticles with Different Binding Affinities

“…SERS peaks of collagen are observed at [Coll] final = 25 μg/mL at 3357, 2934 (ν­(CH 3 ); ν­(CH 2 )), 2877 (ν s (CH 3 )), 1731 (ν­(CO), in COOH of Asp or Glu), 1670 (Amide I (ν­(CO), β-sheet); ν as (COO – )), 1636 (Amide I (ν­(CO), 3 10 -helix); ν as (COO – )), 1444 (δ­(CH 3 ); δ­(CH 2 )), 1410 (ν s (COO – )), 1384 (ν s (COO – )),1321 (τ­(CH 3 ); τ­(CH 2 )), 1264 (Amide III, δ­(N–H)), 1244 (Amide III, ν­(C–N)), 1027 (ν 18a , Phe or Tyr), 934 (ν­(C–C), backbone), and 854 cm –1 (ν­(C–C), Pro ring) (Table S5). − The enhanced ν s (COO – ) peak at 1410 cm –1 could indicate the formation of direct coordinative binding of collagen with Ag atoms.…”

Collagen and Silk Fibroin as Promising Candidates for Constructing Catalysts

“…The catalytic efficacy of catalysts is improved by enhancing active sites, decreasing particle size [ 42 , 43 ], and enhancing the dispersity of active particles [ 44 ]. The active metals (Ag, Cr (III), Fe (III), and Zr (IV) [ 45 , 46 ]) form biological coupling reactions with the hydroxyl, carboxyl, amine, and other functional groups in the protein chains [ 47 , 48 ] and fix them on the collagen fibers. Bi Shi’s research group reported that Fe(III) ions were fixed on collagen fibers to prepare a renewable heterogeneous photocatalytic catalyst for the degradation of Malachite Green MG and Orange II [ 49 , 50 , 51 ].…”