André Luís Condeles, Gabriel Simonetti da Silva, Maria Beatriz Braghetto Hernandes, José Carlos Toledo Junior
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引用次数: 0
Abstract
Under normal physiological conditions, the endogenous Labile Iron Pool (LIP) constitutes a ubiquitous, dynamic, tightly regulated reservoir of cellular ferrous iron. Furthermore, LIP is loaded into new apo-iron proteins, a process akin to the activity of metallochaperones. Despite such importance on iron metabolism, the LIP identity and binding properties have remained elusive. We hypothesized that LIP binds to cell constituents (generically denoted C) and forms an iron complex termed CLIP. Combining this binding model with the established Calcein (CA) methodology for assessing cytosolic LIP, we have formulated an equation featuring two experimentally quantifiable parameters (the concentrations of the cytosolic free CA and CA and LIP complex termed CALIP) and three unknown parameters (the total concentrations of LIP and C and their thermodynamic affinity constant Kd). The fittings of cytosolic CALIP × CA concentrations data encompassing a few cellular models to this equation with floating unknown parameters were successful. The computed adjusted total LIP (LIPT) and C (CT) concentrations fall within the sub-to-low micromolar range while the computed Kd was in the 10−2 µM range for all cell types. Thus, LIP binds and has high affinity to cellular constituents found in low concentrations and has remarkably similar properties across different cell types, shedding fresh light on the properties of endogenous LIP within cells.
期刊介绍:
BioMetals is the only established journal to feature the important role of metal ions in chemistry, biology, biochemistry, environmental science, and medicine. BioMetals is an international, multidisciplinary journal singularly devoted to the rapid publication of the fundamental advances of both basic and applied research in this field. BioMetals offers a forum for innovative research and clinical results on the structure and function of:
- metal ions
- metal chelates,
- siderophores,
- metal-containing proteins
- biominerals in all biosystems.
- BioMetals rapidly publishes original articles and reviews.
BioMetals is a journal for metals researchers who practice in medicine, biochemistry, pharmacology, toxicology, microbiology, cell biology, chemistry, and plant physiology who are based academic, industrial and government laboratories.