Heme is an important cofactor and a regulatory molecule involved in various physiological processes in virtually all living cellular organisms,and it can also serve as the primary iron source for many bacteria,particu...Heme is an important cofactor and a regulatory molecule involved in various physiological processes in virtually all living cellular organisms,and it can also serve as the primary iron source for many bacteria,particularly pathogens.However,excess heme is cytotoxic to cells.In order to meet physiological needs while preventing deleterious effects,bacteria have evolved sophisti-cated cellular mechanisms to maintain heme homeostasis.Recent advances in technologies have shaped our understanding of the molecular mechanisms that govern the biological processes crucial to heme homeostasis,including synthesis,acquisition,utilization,degradation,trafficking,and efflux,as well as their regulation.Central to these mechanisms is the regulation of the heme,by the heme,and for the heme.In this review,we present state-of-the-art findings covering the biochemical,physio-logical,and structural characterization of important,newly identified hemoproteins/systems involved in heme homeostasis.展开更多
Carbon monoxide releasing molecules (CORMs) have been recently developed for research and pharmacological purposes. A considerable amount of studies demonstrated a wide spectrum of biological activities for lipophilic...Carbon monoxide releasing molecules (CORMs) have been recently developed for research and pharmacological purposes. A considerable amount of studies demonstrated a wide spectrum of biological activities for lipophilic CORM-2 (tricarbonyldichlororuthenium (II) dimer). It is generally accepted that the liberated gas provides the specific activities to CORMs, with a little attention paid to any possible effect of complementary core molecules. However, the versatile repertoire of actions attributed to CORM-2 is surprisingly wide for CO, a molecule with the sole chemical activity of binding to ferrous iron in protein prosthetic groups. The study was designed to analyze CORM-2 and its core molecule (“i”CORM) activities at a molecular level. With respect to the hydrophobic nature of the compounds, we followed their interactions with several amphipathic entities: the heme sites of hemoproteins, heme binding proteins and cell membranes. CORM-2/“i”CORM decreased the Soret optical density of hemoglobin and myoglobin, indicating that both compounds interact with the protein amphipathic site in the heme pocket. Pre-addition of CORM-2/“i”CORM to the apo-forms of the plasma heme binding proteins, hemopexin and albumin, partially abolished their heme binding capacity. In contrast, the compounds had no effect on the preformed heme-protein complexes. Addition of CORM-2/“i”- CORM to blood or isolated erythrocytes revealed aggregation of the cells or lysis, depending on the rea-gent-to-cells ratio. It was concluded that the ruthenium containing core molecule of CORM-2 may be physiologically active due to non-specific hydrophobic interactions. As each type of CORMs is expected to have a different mode of action beyond CO activity, their potential therapeutic uses will require clarification.展开更多
Laser Raman spectroscopic studies were carried out on hemoproteins with special reference to epilepsy and compared the data with those of controls. Some of the bands were found approximately at 368.45 cm-1, 424.90 cm-...Laser Raman spectroscopic studies were carried out on hemoproteins with special reference to epilepsy and compared the data with those of controls. Some of the bands were found approximately at 368.45 cm-1, 424.90 cm-1, 625.27 cm-1 and 807.38 cm-1 in case of normal children and at 1749.00 cm-1, 1795 cm-1 and 2000 cm-1 in epileptic children cases. A clear cut picture of the hemoproteins has already given in the literature and very interesting bands were found in the range from 300 cm-1 to 1800 cm-1. Our Raman lines are very effective and peculiar. We did not say anything about the detailing of these bands at this juncture.展开更多
基金This work was supported by the National NaturalScience Foundation of China(Nos.31930003 and 41976087)。
文摘Heme is an important cofactor and a regulatory molecule involved in various physiological processes in virtually all living cellular organisms,and it can also serve as the primary iron source for many bacteria,particularly pathogens.However,excess heme is cytotoxic to cells.In order to meet physiological needs while preventing deleterious effects,bacteria have evolved sophisti-cated cellular mechanisms to maintain heme homeostasis.Recent advances in technologies have shaped our understanding of the molecular mechanisms that govern the biological processes crucial to heme homeostasis,including synthesis,acquisition,utilization,degradation,trafficking,and efflux,as well as their regulation.Central to these mechanisms is the regulation of the heme,by the heme,and for the heme.In this review,we present state-of-the-art findings covering the biochemical,physio-logical,and structural characterization of important,newly identified hemoproteins/systems involved in heme homeostasis.
文摘Carbon monoxide releasing molecules (CORMs) have been recently developed for research and pharmacological purposes. A considerable amount of studies demonstrated a wide spectrum of biological activities for lipophilic CORM-2 (tricarbonyldichlororuthenium (II) dimer). It is generally accepted that the liberated gas provides the specific activities to CORMs, with a little attention paid to any possible effect of complementary core molecules. However, the versatile repertoire of actions attributed to CORM-2 is surprisingly wide for CO, a molecule with the sole chemical activity of binding to ferrous iron in protein prosthetic groups. The study was designed to analyze CORM-2 and its core molecule (“i”CORM) activities at a molecular level. With respect to the hydrophobic nature of the compounds, we followed their interactions with several amphipathic entities: the heme sites of hemoproteins, heme binding proteins and cell membranes. CORM-2/“i”CORM decreased the Soret optical density of hemoglobin and myoglobin, indicating that both compounds interact with the protein amphipathic site in the heme pocket. Pre-addition of CORM-2/“i”CORM to the apo-forms of the plasma heme binding proteins, hemopexin and albumin, partially abolished their heme binding capacity. In contrast, the compounds had no effect on the preformed heme-protein complexes. Addition of CORM-2/“i”- CORM to blood or isolated erythrocytes revealed aggregation of the cells or lysis, depending on the rea-gent-to-cells ratio. It was concluded that the ruthenium containing core molecule of CORM-2 may be physiologically active due to non-specific hydrophobic interactions. As each type of CORMs is expected to have a different mode of action beyond CO activity, their potential therapeutic uses will require clarification.
文摘Laser Raman spectroscopic studies were carried out on hemoproteins with special reference to epilepsy and compared the data with those of controls. Some of the bands were found approximately at 368.45 cm-1, 424.90 cm-1, 625.27 cm-1 and 807.38 cm-1 in case of normal children and at 1749.00 cm-1, 1795 cm-1 and 2000 cm-1 in epileptic children cases. A clear cut picture of the hemoproteins has already given in the literature and very interesting bands were found in the range from 300 cm-1 to 1800 cm-1. Our Raman lines are very effective and peculiar. We did not say anything about the detailing of these bands at this juncture.
