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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Conjugated proteins or Heteroproteins consist of a simple protein combined with a nonprotein component. The nonprotein component is called a prosthetic group (36, 47). A protein without its prosthetic group is called an apoprotein. A protein molecule combined with its prosthetic group forms a heteroprotein. Prosthetic groups play an important role in the function of proteins. Conjugated proteins are classified according to the nature of their prosthetic groups. They include glycoproteins, lipoproteins, metalloproteins, hemoproteins, phosphoproteins, and so on. Glycoproteins contain a carbohydrate component. Lipoproteins are proteins containing lipid molecules such as cholesterol which are divided into High-Density Lipoprotein (HDL) or ‘good’ cholesterol and Low-Density Lipoprotein (LDL) or ‘bad’ cholesterol. Metalloproteins contain metal ions (iron, calcium, copper, zinc, and molybdenum). Phosphoproteins contain phosphate groups, while hemoproteins or chromoproteins possess heme groups such as hemoglobin. Hemoglobin is the metalloprotein containing iron for the transport of oxygen in the red blood cells of all mammals (36, 47).
Metallothionein
Published in Lars Friberg, Tord Kjellström, Carl-Gustaf Elinder, Gunnar F. Nordberg, Cadmium and Health: A Toxicological and Epidemiological Appraisal, 2019
Carl-Gustaf Elinder, Monica Nordberg
In 1957, Margoshes and Vallee62 reported the isolation of a low molecular weight cadmium-binding protein from horse renal cortex. Subsequent work by Kägi and Vallee47,48 resulted in the purification of a metalloprotein, with a molecular size of about 10,000 daltons, which they named metallothionein because of its high content of metals (cadmium and zinc) and sulfur. Later studies have shown that the actual molecular weight is about 6,500,72 based on amino acid residues. This metalloprotein was shown to have many unique physicochemical properties (Table 1).
The Glutathione Redox State and Zinc Mobilization from Metallothionein and Other Proteins with Zinc–Sulfur Coordination Sites
Published in Christopher A. Shaw, Glutathione in the Nervous System, 2018
The amount of zinc (2–3 g) and its daily requirement (2–7 mg, depending on its availability in the diet) in a 70-kg adult human are close to those of iron (4–5 g and about 10 mg, respectively). It is also true that whereas the functions of iron in oxidoreduction (cytochromes) and oxygen transport and storage (hemoglobin and myoglobin) are specific and well defined, zinc-dependent functions are much more widespread. Thus, zinc is an essential element of paramount importance for growth and development, metabolism, the immune response, gene expression, and neurotransmission, among others. Over the past 10 years, expanding progress in the recognition of zinc-dependent functions (Vallee and Falchuk 1993) and in the elucidation of the molecular structure of many different motifs of zinc sites in proteins (Vallee and Auld 1993) has stimulated interest in this element in almost all branches of the biomedical sciences. Virtually all roles of zinc so far are linked to function and structure of proteins. In fact, zinc-containing proteins form a much larger group than any of the other metalloproteins. More than 200 zinc enzymes have been recognized, in all seven of the classes defined by the commission for enzyme nomenclature of the International Union of Biochemistry and Molecular Biology (Vallee and Falchuk 1993), and an estimated 500 zinc finger genes of just one of the many classes exist in humans (Becker et al. 1995).
Determination of ultra-trace metal-protein interactions in co-formulated monoclonal antibody drug product by SEC-ICP-MS
Published in mAbs, 2023
Laurence Whitty-Léveillé, Zachary L. VanAernum, Jorge Alexander Pavon, Christa Murphy, Katie Neal, William Forest, Xinliu Gao, Wendy Zhong, Douglas D. Richardson, Hillary A. Schuessler
Herein, we describe an SEC-ICP-MS method capable of measuring metal-protein interactions present in a therapeutic drug product consisting of two co-formulated mAbs at ultra-trace levels. We first use ferritin and Cu,Zn-superoxide dismutase, two metalloproteins containing transition metals, to develop the method and provide proof of concept. We then analyzed co-formulated mAbs stressed using stainless steel coupons to simulate the level of metal that may be introduced through drug substance manufacturing. Moreover, we calculate the relative quantitation of metal-protein interaction and free-metal, using a relative peak area quantification approach combined with total metal determination. Our technique led to an improved understanding of metal-protein interactions in biologic formulations, and more importantly serves as a tool to better understand the role of metal-protein interactions in metal-induced protein degradation often associated with biologics manufacturing.
Potential of Application of Iron Chelating Agents in Ophthalmic Diseases
Published in Seminars in Ophthalmology, 2021
Alireza Ghaffarieh, Joseph B. Ciolino
Understanding how iron metabolism and infectious agents interact might suggest new methods to control the disease. Investigations indicate that iron loading can exacerbate viral disease. Therefore, it is plausible that reducing cellular or body iron stores could influence disease pathogenesis, as seems to be the case for viral infection.4 Iron withdrawal is part of the natural innate immune response in infection. During inflammation and infection, a “hypoferremic response” is observed (anemia of inflammation).5 Replication of HIV-1, Herpes simplex, CMV, HBV, HCV, Epstein-Barr virus, Parvovirus B-19, Coxsackie-B, and Herpes Zoster can be influenced by iron.6,7 Hence, decreasing the availability of iron may inhibit viral replication. Almost a third of all viral proteins are metalloproteins, with some responsible for a wide variety of essential viral functions.4,8
Understanding hydrogen sulfide signaling in neonatal airway disease
Published in Expert Review of Respiratory Medicine, 2021
Marta Schiliro, Colleen M Bartman, Christina Pabelick
H2S can be reduced by iron-heme proteins and can be directly bound by heme moieties in metalloproteins. Redox reactions between H2S and heme generate sulfide oxidation products concurrently with iron reduction yielding HS•. This highly reactive HS• leads to protein persulfidation or even interaction with other gasotransmitters such as NO [151–155]. Sulfide redox reactions with heme-containing proteins have been described with regard to cytochrome c oxidase (COX) [156–159], hemoglobin and myoglobins [156,160,161], and peroxidases [162–165]. The toxicity of H2S may be through sulfide’s inhibition of oxygen binding through mitochondrial respiration and particularly via redox reactions of COX [156]. However, this effect appears dose-dependent considering lower concentrations of H2S can actually fuel mitochondrial respiration through oxidative phosphorylation [157,158]. Interactions between H2S and metalloproteins highlight signaling mechanisms of H2S and its role in cellular bioenergetic function (discussed further in mitochondrial section below). The deleterious versus beneficial cellular effects based on high versus low concentrations of H2S, respectively, demands further investigation to understand how reactions with metalloproteins manipulates downstream pathways. Mechanisms of chemical reactions for H2S on metalloproteins are outside the scope of this review, so we direct the reader to reviews focused on this topic [124,166].