Escherichia coli iron enterobactin uptake monitored by Moessbauer spectroscopy

Journal Article · Fri Aug 01 00:00:00 EDT 1986 · J. Bacteriol.; (United States)

OSTI ID:6937252

Matzanke, B F; Ecker, D J; Yang, T S; Huynh, B H; Mueller, G; Raymond, K N

Iron uptake by Escherichia coli under aerobic conditions of iron deficiency is mediated by a highly stable ferric enterobactin (Fe(ent)/sup 3 -/) siderophore complex. Moessbauer spectroscopy has been used to monitor the fate of the iron as /sup 57/Fe(ent) was taken up by the cells. Osmotic shock experiments were used to distinguish between the iron present in the periplasmic space and that in the cytoplasm of the cell. Iron delivery by a synthetic analog of enterobactin, 1,3,5-N,N', N''-tris-(2,3-dihydroxybenzoyl)triaminomethylbenzene (MECAM), was also studied. Although Fe-MECAM was transported at the same rate as was Fe(ent) across the outer membrane and was apparently accumulated in the periplasmic space, the subsequent behaviors of Fe(ent) and Fe-MECAM were very different. After more than 30 min, a major fraction of the iron originally absorbed as ferric enterobactin appeared as Fe(II), apparently in the cytoplasm of the cell. However, little iron was delivered to the cytoplasm by the MECAM complex. The differences in specificity of these two stages of iron uptake by E. coli are discussed.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6937252
• Journal Information: J. Bacteriol.; (United States), Vol. 167:2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
IRON COMPLEXES
MEMBRANE TRANSPORT
STRUCTURAL CHEMICAL ANALYSIS
ESCHERICHIA COLI
GAMMA SPECTROSCOPY
IRON 57
MOESSBAUER EFFECT
TRACER TECHNIQUES
UPTAKE
BACTERIA
COMPLEXES
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
IRON ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MICROORGANISMS
NUCLEI
SPECTROSCOPY
STABLE ISOTOPES
TRANSITION ELEMENT COMPLEXES
550201* - Biochemistry- Tracer Techniques