Iron environment in ferritin with large amounts of phosphate, from Azotobacter vinelandii and horse spleen, analyzed using Extended X-ray Absorption fine Structure (EXAFS)

Journal Article · Tue Jan 09 00:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00453a035· OSTI ID:7192696

Rohrer, J S; Islam, Q T; Sayes, D E; Theil, E C ^[1]; Watt, G D ^[2]

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1. North Carolina State Univ., Raleigh (USA)
2. Univ. of Colorado, Boulder (USA)

The iron core of proteins in the ferritin family displays structural variations that includes phosphate content was well as the number and the degree of ordering of the iron atoms. Earlier studies had shown that ferritin iron cores naturally high in phosphate, e.g., Azotobacter vinelandii (AV) ferritin had decreased long-range order. Here, the influence of phosphate on the local structure around iron in ferritin cores is reported, comparing the EXAFS of AV ferritin, reconstituted ferritin and native horse spleen ferritin. In contrast, when the phosphate content was high in AV ferritin and horse spleen ferritin reconstituted with phosphate, the average iron atom had five to six phosphorus neighbors at 3.17 {angstrom}. Moreover, the number of detectable iron neighbors was lower when phosphate was high or present during reconstitution and the interatomic distance was longer indicating that some phosphate bridges neighboring iron atoms. However, the decrease in the number of detectable iron-iron neighbors compared to HSF and the higher number of Fe-P interactions relative to Fe-Fe interactions suggest that some phosphate ligands were chain termini, or blocked crystal growth, and/or introduced defects which contributed both to the long-range disorder and to altered redox properties previously observed in AV ferritin.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7192696
• Journal Information: Biochemistry; (USA), Vol. 29:1; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
FERRITIN
RADIATION ABSORPTION ANALYSIS
ABSORPTION SPECTRA
FLUORESCENCE
FOURIER TRANSFORMATION
HORSES
IRON COMPOUNDS
PHOSPHATES
SPLEEN
X RADIATION
X-RAY SPECTRA
ANIMALS
BODY
CHEMICAL ANALYSIS
COMPLEXES
ELECTROMAGNETIC RADIATION
INTEGRAL TRANSFORMATIONS
IONIZING RADIATIONS
IRON COMPLEXES
LUMINESCENCE
MAMMALS
METALLOPROTEINS
NONDESTRUCTIVE ANALYSIS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PROTEINS
RADIATIONS
SPECTRA
TRANSFORMATIONS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
550602* - Medicine- External Radiation in Diagnostics- (1980-)