Heme enzymes are ubiquitous in nature. Although these contain the same Fe-protoporphyrin IX cofactor their active site, they exhibit different structural and functional activities. This brief review focuses on reasons for this diversity mentions some attempts to mimic activity of heme enzymes. It also briefly discusses efforts expand catalytic repertoire enable new chemical transformations.

5-Aminolevulinic acid (ALA) is the rate-limiting intermediate in heme biosynthesis vertebrate species; a reaction catalyzed by mitochondrial ALA synthase 1 (ALAS1) enzyme. Previously we reported that knockdown of ubiquitously expressed ALAS1 gene mice disrupts normal glucose metabolism, attenuates function and results prediabetic like phenotype when animals pass 20-weeks age (Saitoh et al., 201...

Shigella dysenteriae serotype 1, a major cause of bacillary dysentery in humans, can use heme as a source of iron. Genes for the transport of heme into the bacterial cell have been identified, but little is known about proteins that control the fate of the heme molecule after it has entered the cell. The shuS gene is located within the heme transport locus, downstream of the heme receptor gene ...

Background and objectives: Viola odorata L. is a grassy plant that grows in the humid regions and has been used to treat liver diseases and complicated and tropical fevers in Iranian traditional medicine (ITM). V. odorata has cold and humid temperament while the temperament of fever which is the most important symptom of malaria is the opposite. Antimalarial a...

Horseradish peroxidase (HRP), has gained significant interests in biotechnology, especially in biosensor field and diagnostic test kits. Hence, its solvent-exposed lysine residues 174, 232, and 241 have been frequently modified with the aim of improving its stability and catalytic efficiency. In this computational study, we investigated the effects of Lys-to-Glu substitutions on HRP structure t...

A previously developed spectrometer for broadband electron paramagnetic resonance (EPR) spectroscopy of dilute randomly oriented systems has been considerably modified to extend the frequency reach down hundred MHz range and boost concentration sensitivity by 1 2 orders magnitude. The instrument is now suitable study biological in particular metalloproteins. As a proof concept, examples from cl...

In the present study, we investigated the effect of a new anticancer Pd(II) complex, 1,10-phenanthroline-n-butyl dithiocarbamato Pd(II) nitrate, on the heme releasing from human hemoglobin (Hb) as well as alterations in the structure and function of Hb using different spectroscopic methods of UV-Vis, fluorescence and circular dichroism (CD)at two temperatures of 25 and 37 °C. Fluorescence data ...

An iron-containing, tetrapyrrole ring, heme is an essential prosthetic group in an array of proteins that comprehensively affect cellular function and metabolism; yet "free" heme in sufficient amounts can be damaging to the kidney and other organs because of its bioreactivity and pro-oxidant effects. This review discusses the cellular metabolism of heme in health and disease and covers such are...

Oxygen activation in all heme enzymes requires the formation of high oxidation states iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and II. The nature heme—and whether it is an FeIV=O or FeIV-OH species—is important for controlling reactivity across groups enzymes. most recent evidence indicates that unprotonated species. For II, not unambiguously estab...