PMID- 15649151
OWN - NLM
STAT- MEDLINE
DCOM- 20050330
LR  - 20161021
IS  - 0893-5785 (Print)
IS  - 0893-5785 (Linking)
VI  - 18
IP  - 1
DP  - 2005 Feb
TI  - Metal-ion interactions and the structural organization of Sepia eumelanin.
PG  - 42-8
AB  - The structural organization of melanin granules isolated from ink sacs of Sepia 
      officinalis was examined as a function of metal ion content by scanning electron 
      microscopy and atomic force microscopy. Exposing Sepia melanin granules to 
      ethelenediaminetetraacetic acid (EDTA) solution or to metal salt solutions 
      changed the metal content in the melanin, but did not alter granular morphology. 
      Thus ionic forces between the organic components and metal ions in melanin are 
      not required to sustain the natural morphology once the granule is assembled. 
      However, when aqueous suspensions of Sepia melanin granules of varying metal 
      content are ultra-sonicated, EDTA-washed and Fe-saturated melanin samples lose 
      material to the solution more readily than the corresponding Ca(II) and 
      Mg(II)-loaded samples. The solubilized components are found to be 
      5,6-dihydroxyindole-2-carboxylic acid (DHICA)-rich constituents. Associated with 
      different metal ions, Na(I), Ca(II) and Mg(II) or Fe(III), these DHICA-rich 
      entities form distinct two-dimensional aggregation structures when dried on the 
      flat surface of mica. The data suggest multiply-charged ions play an important 
      role in assisting or templating the assembly of the metal-free organic components 
      to form the three-dimensional substructure distributed along the protein scaffold 
      within the granule.
FAU - Liu, Yan
AU  - Liu Y
AD  - Department of Chemistry, Duke University, Durham, NC, USA.
FAU - Simon, John D
AU  - Simon JD
LA  - eng
GR  - GM-56882/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Denmark
TA  - Pigment Cell Res
JT  - Pigment cell research
JID - 8800247
RN  - 0 (Ions)
RN  - 0 (Melanins)
RN  - 0 (Metals)
RN  - 12627-86-0 (eumelanin)
SB  - IM
MH  - Animals
MH  - Ions
MH  - Melanins/*chemistry/isolation & purification
MH  - Melanosomes/*chemistry/ultrastructure
MH  - Metals
MH  - Microscopy, Atomic Force
MH  - Mollusca/*chemistry
EDAT- 2005/01/15 09:00
MHDA- 2005/03/31 09:00
CRDT- 2005/01/15 09:00
PHST- 2005/01/15 09:00 [pubmed]
PHST- 2005/03/31 09:00 [medline]
PHST- 2005/01/15 09:00 [entrez]
AID - PCR197 [pii]
AID - 10.1111/j.1600-0749.2004.00197.x [doi]
PST - ppublish
SO  - Pigment Cell Res. 2005 Feb;18(1):42-8. doi: 10.1111/j.1600-0749.2004.00197.x.