Isolation from Acid-Fast Bacteria of a Growth-Factor for Mycobacterium johnei and of a Precursor of Phthiocol

Francis, Juan Miguel Abdo; Madinaveitia, J.; Macturk, H. M.; Snow, G. A.

doi:10.1038/163365b0

Cited by 57 publications

(21 citation statements)

References 5 publications

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“…(TWORT and INGRAM, 1912). This growth factor has been extracted from Mycobacterium phlei and was named M (myeobaetin) (FRANCIS et al, 1949;FRANCIS et al, 1953). Although the iron-ehelating property of M has been recognized from the time of its isolation, it has been viewed as an essential growth factor principalIy for M. paratuberculosis.…”

Section: Alleviation Of Serum Bacteriostasis With Iron-binding Bacmentioning

confidence: 99%

The Role of Iron in Bacterial Infections, with Special Consideration of Host-Tubercle Bacillus Interaction

Kochan

1973

Current Topics in Microbiology and Immunology

213

124

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Section: Alleviation Of Serum Bacteriostasis With Iron-binding Bacmentioning

confidence: 99%

The Role of Iron in Bacterial Infections, with Special Consideration of Host-Tubercle Bacillus Interaction

Kochan

1973

Current Topics in Microbiology and Immunology

213

124

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“…50 Mycobactins from Gram-positive Mycobacteria and the closely related nocobactins from Nocardia embody a series of lipid-soluble siderophores located in the lipid-rich boundary layers of these bacteria (Figure 2(c)). 51 The X-ray structure revealed that iron binding in mycobactins is accomplished by two hydroxamates, a phenolate group, and oxazoline nitrogen.…”

Section: Siderophores With Mixed Ligands and Heterocyclic Chelating Gmentioning

confidence: 99%

Iron Transport: Siderophores

Matzanke¹

2005

Encyclopedia of Inorganic and Bioinorganic Chemistry

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Siderophores (from the Greek: iron carrier) are low molecular mass (500–1500 Da) iron chelators that are synthesized in bacteria and fungi under conditions of iron deficiency. Siderophores exhibit extraordinarily high complex formation constants for ferric iron with β‐values ranging from 10 20 to approximately 10 50 . Fe 2+ ‐siderophores are some 20 orders of magnitude less stable than their Fe 3+ counterparts. The d5 electronic configuration of Fe 3+ rules out any crystal field stabilization energy and makes ferric iron complexes relatively labile with respect to isomerization and ligand exchange. Siderophores display a selectivity for iron that is reflected in the corresponding complex stability constants that are higher with Fe 3+ than with Al 3+ , or with bivalent cations like Ca 2+ , Cu 2+ or Zn 2+ . Microorganisms excrete desferrisiderophores in order to scavenge iron from the environment. The competition for iron by siderophores, the mechanisms of siderophore uptake through microbial membranes, and the intracellular pathways of siderophore‐iron utilization strongly depend on thermodynamic, kinetic, and structural features of the ferric iron siderophore complexes. The structural features of siderophores are diverse. The ligating groups contain oxygen atoms of hydroxamate, catecholate, α‐hydroxy carboxylic and salicylic acids, or oxazoline and thiazoline nitrogen. Reduction potentials of ferric siderophore complexes vary between −700 and −150 mV. In particular at the low potential end below −450 mV, special biological strategies of reductive iron removal are required because these potentials are too negative for typical cellular reductases. The coordination and redox chemistry of siderophores is also reflected in the mechanisms of siderophore‐mediated iron uptake in microorganisms. A classic example is the intracellular removal of iron from enterobactin. The permeation of cell walls or bacterial membranes by siderophores is in most microbes a highly specific process requiring an array of up to eight proteins. The advent of modern molecular biology delivered a cornucopia of methods enabling high‐yield production of specific gene products relevant to siderophore synthesis and transport, analyses of structure‐function relationships (employing site directed mutagenesis), and detailed insights into the regulation of the corresponding processes. One siderophore, ferrioxamine B, serves as a detoxifier in iron overload diseases and in the treatment of β‐thalassemia. Siderophores and siderophore analogs also play a role in MRI and are employed as basic models for actinide chelators in order to remove these metals from the environment or from a contaminated body.

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“…Mycobactins were amongst the very first bacterial siderophores to be described (Francis et al 1949(Francis et al , 1953. The elegant work of Snow and colleagues in the 1950s and 1960s elucidated the structures of 10 mycobactins from different mycobacteria (see Fig. 14.6).…”

Section: Structuresmentioning

confidence: 99%

Iron Metabolism

Ratledge

1999

Mycobacteria

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Isolation from Acid-Fast Bacteria of a Growth-Factor for Mycobacterium johnei and of a Precursor of Phthiocol

Cited by 57 publications

References 5 publications

The Role of Iron in Bacterial Infections, with Special Consideration of Host-Tubercle Bacillus Interaction

The Role of Iron in Bacterial Infections, with Special Consideration of Host-Tubercle Bacillus Interaction

Iron Transport: Siderophores

Iron Metabolism

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