Tyrosine ligands to iron in hemerythrin

Rill, Randolph L.; Klotz, Irving M.

doi:10.1016/0003-9861(70)90222-5

Cited by 18 publications

(12 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also find a high degree of correspondence between the P. gouldii sequence and bulky side chains in other parts of our map. Chemical studies have implicated both histidine and tyrosine as ligands (1,(4)(5)(6)(7)(8), and the appearance, as noted above, of these residues as ligands at the vertices of triangles A and C (Fig. 1) is consistent with these studies.…”

supporting

confidence: 75%

“…1) is consistent with these studies. Moreover, the coordination of Tyr at only one of the Fe atoms in a pair is consistent with the observation that when the tyrosine residues are modified by treatment with tetranitromethane only one of the two Fe atoms is lost (5,6). Mossbauer spectra, on the other hand, are interpreted as indicating similar environments for the Fe atoms in met-and deoxyhemerythrin (15).…”

supporting

confidence: 68%

“…Although chemical and physical studies have revealed many details of the hemerythrin structure (4)(5)(6)(7)(8)(9)(10), until recently no three-dimensional model was available which could serve to correlate these studies. The structure of myohemerythrin, which is thought to be similar to the subunit of hemerythrin, has been reported at 5.5 A resolution by Hendrickson et al (11), and more recently the structures of hemerythrins from Themiste (Dendrostomum) dyscritum and Phascolopsis (Golfingia) gouldii have been solved at 5 A and 5.5 A resolutions respectively (12,13).…”

mentioning

confidence: 99%

“…Intensity data to 2.8 A resolution were collected, as in the 5 A resolution study (12), by a five-step scan technique for crystals of the native protein and one mercury iodide derivative. Phases were determined from the single derivative by use of anomalous scattering from the Hg and I atoms as was done in the earlier study.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Structure of the iron complex in methemerythrin.

Stenkamp¹,

Sieker²,

Jensen³

1976

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The coordination of the ligands about the iron atoms in methemerythrin from Themiste dyscritum has been deduced from a 2.8 A resolution electron density map. The complex can be described in terms of two trigonal antiprisms about the pair of iron atoms in each subunit, the antiprisms having one face in common. Ligands at eight of the nine coordination positions are protein side chains, the ninth presumably being water. Comparison of the electron density map for T. dyscritum methemerythrin with the sequence of Phascolopsis gouldii hemerythrin suggests six aromatic side chain ligands (five histidine and one tyrosine) and two nonaromatic side chain ligands. The latter provide atoms at two of the three vertices of the face shared by the two antiprisms, and these along with the presumed water at the third vertex form bridges between the iron atoms of each pair.

show abstract

supporting

confidence: 75%

supporting

confidence: 68%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Structure of the iron complex in methemerythrin.

Stenkamp¹,

Sieker²,

Jensen³

1976

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…pyroides and P. agassizii proteins, the iron analyses were performed by photometry of the I ,I 0-phenanthroline complex of iron(I1) extracted from the protein. The procedure of Rill and Klotz (1970) was modified by the substitution of 1 M N a H S 0 3 for hydroxylamine to improve reproducibility. Ferrous ethylenediammonium sulfate (G. F. Smith Chemical Co., primary standard grade) gave t = I 1 200 f 200 M-' cm-' at 510 nm under these conditions.…”

Section: Methodsmentioning

confidence: 99%

Comparison of hemerythrins from four species of sipunculids by optical absorption, circular dichroism, fluorescence emission, and resonance Raman spectroscopy

Dunn¹,

Addison²,

Bruce³

et al. 1977

Biochemistry

View full text Add to dashboard Cite

Resonance Raman, optical absorption, circular dichroic, and fluorescence emission spectroscopy of hemerythrins from four species of sipunculids (Phascolopsis gouldii, Phascolosoma agassizii, Themiste dyscritium, and Themiste pyroides) reveals no major differences in their active site or tertiary structures. This precludes any change in iron ligands or coodination geometry and makes it unlikely that the active-site structures of P. gouldii and T. dyscritum hemerythrins could be as disparate as indicated by present crystallographic interpretations (Stenkamp, R. E., Sieker, L. C., and Jensen, L. H. (1976), Proc. Natl. Acad. Sci. U.S.A. 73, 349; Klotz, I. M., Klippenstein, G. L., and Hendrickson, W. A. (1976), Science 192, 335). Resonance Raman enhancement profiles of the stretching modes involving coordinated dioxygen maximize with excitation at approximately 525 nm, and correspond to the circular dichroic (CD) transition at approximately 520 nm. For coordinated azide modes in metazidohemerythrins these profiles maximize with excitation at approximately 505 nm corresponding to the 500-nm CD transition. Hemerythrins also possess another resonance Raman peak at approximately 510 cm-1 which show maximum intensity enhancement at approximately 530 nm and this vibration is most likely associated with a permanent iron ligand.

show abstract