The ubiquitously expressed iron storage protein ferritin plays a central role in maintaining cellular iron homeostasis. Cytosolic ferritins are composed of heavy (H) and light (L) subunits that co-assemble into a hollow spherical shell with an internal cavity where iron is stored. The ferroxidase activity of the ferritin H chain is critical to store iron in its Fe3+ oxidation state, while the L...

Human ferritins sequester and store iron as a stable FeOOH((s)) mineral core within a protein shell assembled from 24 subunits of two types, H and L. Core mineralization in recombinant H- and L-subunit homopolymer and heteropolymer ferritins and several site-directed H-subunit variants was investigated to determine the iron oxidation/hydrolysis chemistry as a function of iron flux into the prot...

Although iron is the fourth most abundant element in the Earth's crust, bioavailable iron limits marine primary production in about one third of the ocean. This lack of iron availability has implications in climate change because the removal of carbon dioxide from the atmosphere by phytoplankton requires iron. Using literature values for global fish biomass estimates, and elemental composition ...

Previous studies of microbial communities in deep-sea hydrothermal ferric deposits have demonstrated that members of Zetaproteobacteria play significant ecological roles in biogeochemical iron-cycling. However, the ecophysiological characteristics and interaction between other microbial members in the habitat still remain largely unknown. In this study, we investigated microbial communities in ...

Iron is crucial for the survival of living cells, particularly the human pathogen Mycobacterium tuberculosis (M.tb) which uses multiple strategies to acquire and store iron. M.tb synthesizes high affinity iron chelators (siderophores), these extract iron from host iron carrier proteins such as transferrin (Tf) and lactoferrin (Lf). Recent studies have revealed that M.tb may also relocate severa...

Iron is an essential nutrient for all living organisms. Iron is required for the synthesis of chlorophyll and of several photosynthetic electron transport proteins and for the reduction of CO2, SO4(2-), and NO3(-) during the photosynthetic production of organic compounds. Iron concentrations in vast areas of the ocean are very low (<1 nM) due to the low solubility of iron in oxic seawater. Low ...

Rittu Surjit Chandel*, Gangadhar Chatterjee, Leela G Abichandani Department of Biochemistry, Grant Govt. Medical College & Sir JJ Group of Hospitals. Mumbai. Maharashtra. Background: Thyroid hormones play an important physiological role to maintain balance of metabolism of entire human body. Erythrocyte abnormalities are frequently associated with thyroid disorder. Subclinical hypothyroidism, o...

BACKGROUND Macrophages play a key role in iron homeostasis. In peripheral tissues, they are known to polarize into classically activated (or M1) macrophages and alternatively activated (or M2) macrophages. Little is known on whether the polarization program influences the ability of macrophages to store or recycle iron and the molecular machinery involved in the processes. DESIGN AND METHODS ...

The efficacy of iron therapy in nutritional anaemia, which has been shown to be of such common occurrence in infants and adults (Mackay"6; Faber6; Davidson et al'; Fullerton') is apparently dependent on the administration of large doses of iron if given orally (Heath"; Witts"). In this connection it is interesting to recall that the use of large doses was first advocated in 1832 by Blaud'. Only...

The behaviours of as-received and recrystallised (homogenised) MA 956, an Al-containing Cr-rich ferritic stainless steel, aged at 475 "C for up to 2900 hours have been investigated. Atom probe microanalysis of the decomposition products revealed that A1 did not partition significantly to the Fe-rich phase after =600 hours ageing, contrary to thermodynamic predictions. Ageing to 2900 hours, howe...