A Zirconium Metal-Organic Framework with SOC Topological Net for Catalytic Peptide Bond Hydrolysis

The discovery of nanozymes for selective fragmentation of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the detailed catalytic properties of a microporous zirconium carboxylate metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features an excellent catalytic activity and selectivity, a good tolerance toward reaction conditions covering a wide range of different pH values, and importantly, an exceptional recycling ability associated with easy regeneration process. Taking into account the excellent catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and an outstanding chemical and architectural stability, our finding suggests that MIP-201 may be a promising and practical alternative to the current commercially available catalysts for peptide bond hydrolysis.

A Zirconium Metal-Organic Framework with SOC Topological Net for Catalytic Peptide Bond Hydrolysis

The discovery of nanozymes for selective fragmentation of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the detailed catalytic properties of a microporous zirconium carboxylate metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features an excellent catalytic activity and selectivity, a good tolerance toward reaction conditions covering a wide range of different pH values, and importantly, an exceptional recycling ability associated with easy regeneration process. Taking into account the excellent catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and an outstanding chemical and architectural stability, our finding suggests that MIP-201 may be a promising and practical alternative to the current commercially available catalysts for peptide bond hydrolysis.

A Zirconium Metal-Organic Framework with SOC Topological Net for Catalytic Peptide Bond Hydrolysis

<div>The discovery of nanozymes for selective cleavage of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the detailed catalytic properties of a microporous zirconium carboxylate metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features an excellent catalytic activity and selectivity, a good tolerance toward reaction conditions covering a wide range of different pH values, and importantly, an exceptional recycling ability associated with easy regeneration process. Taking into account the excellent catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and an outstanding chemical and architectural stability, our finding suggests that MIP-201 may be a promising and practical alternative to the current commercially available catalysts for peptide bond hydrolysis.</div>

A Zirconium Metal-Organic Framework with SOC Topological Net for Catalytic Peptide Bond Hydrolysis

<div>The discovery of nanozymes for selective cleavage of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the detailed catalytic properties of a microporous zirconium carboxylate metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features an excellent catalytic activity and selectivity, a good tolerance toward reaction conditions covering a wide range of different pH values, and importantly, an exceptional recycling ability associated with easy regeneration process. Taking into account the excellent catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and an outstanding chemical and architectural stability, our finding suggests that MIP-201 may be a promising and practical alternative to the current commercially available catalysts for peptide bond hydrolysis.</div>

ЭЛЕКТРОСТАТИЧЕСКОЕ ВЗАИМОДЕЙСТВИЕ ГЛОБИНОВ С ФОСФОЛИПИДНЫМИ МЕМБРАНАМИ

The present study aimed to analyze the role of electrostatic interactions contributing to the stability of the native conformations of the heme group in the structure of sperm whale myoglobin (SWMb), horse heart myoglobin (HHMb), hemoglobin I (HbI) from the botfly Gasterophilus intestinalis (giHbI) and monomeric and dimeric hemoglobins HbI and HbII from the mollusk Lucina pectinata (lpHbI and lpHbII) as well as investigate a possible reason of destabilization due to interaction with negatively charged phospholipid membranes. It was shown that the native conformation of the heme cavity in these globins, both in its proximal and distal sides, is sustained by a system of hydrogen bonds involving the proximal and distal protein residues, both heme propionic acid groups and the nearby polar amino acids on the protein surface (His, Arg, Lys). The hydrogen bond network in the proximal part of the heme pocket controls the position of the Fe atom outside or in the protoporphyrin plane, affecting the efficiency of ligand binding, while in the distal part of the heme cavity the hydrogen bond network formed with the participation of the distal protein residue (HisE7 in swMb, hhMb and giHbI, and GlnE7 in lpHbII) should, apparently, stabilize conformation where the protein is able to donate hydrogen to O2 ligand...

Catalase-Like Antioxidant Activity is Unaltered in Hypochlorous Acid Oxidized Horse Heart Myoglobin

Activated neutrophils release myeloperoxidase that produces the potent oxidant hypochlorous acid (HOCl). Exposure of the oxygen transport protein horse heart myoglobin (hhMb) to HOCl inhibits Iron III (Fe(III))-heme reduction by cytochrome b5 to oxygen-binding Iron II (Fe(II))Mb. Pathological concentrations of HOCl yielded myoglobin oxidation products of increased electrophoretic mobility and markedly different UV/Vis absorbance. Mass analysis indicated HOCl caused successive mass increases of 16 a.m.u., consistent serial addition of molecular oxygen to the protein. By contrast, parallel analysis of protein chlorination by quantitative mass spectrometry revealed a comparatively minor increase in the 3-chlorotyrosine/tyrosine ratio. Pre-treatment of hhMb with HOCl affected the peroxidase reaction between the hemoprotein and H2O2 as judged by a HOCl dose-dependent decrease in spin-trapped tyrosyl radical detected by electron paramagnetic resonance (EPR) spectroscopy and the rate constant of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) oxidation. By contrast, Mb catalase-like antioxidant activity remained unchanged under the same conditions. Notably, HOCl-modification of Mb decreased the rate of ferric-to-ferrous Mb reduction by a cytochrome b5 reductase system. Taken together, these data indicate oxidizing HOCl promotes Mb oxidation but not chlorination and that oxidized Mb shows altered Mb peroxidase-like activity and diminished rates of one-electron reduction by cytochrome b5 reductase, possibly affecting oxygen storage and transport however, Mb-catalase-like antioxidant activity remains unchanged.

The effect of the buffer solution on the adsorption and stability of horse heart myoglobin on commercial mesoporous titanium dioxide: a matter of the right choice

An insight into the buffer role in protein stability and adsorption on mesoporous materials.