PMID- 21923179
OWN - NLM
STAT- MEDLINE
DCOM- 20120315
LR  - 20121115
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 115
IP  - 43
DP  - 2011 Nov 3
TI  - UV-absorption spectra of melanosomes containing varying 5,6-dihydroxyindole and 
      5,6-dihydroxyindole-2-carboxylic acid content.
PG  - 12624-31
LID - 10.1021/jp2060624 [doi]
AB  - Central to understanding the photochemical properties of melanosomes is a direct 
      measurement of their absorption coefficients. Herein, the absorption spectra of 
      intact melanosomes of varying molecular compositions and embryonic origins were 
      measured and compared over the spectral range from 245 to 310 nm. The absorption 
      spectra of melanosomes predominately comprised of the eumelanin pigment were 
      found to differ significantly from their constituent precursor molecules, 
      5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). This 
      difference was most notable in the UV-A region and indicates that the electronic 
      structures of the monomeric building blocks, DHICA in particular, are 
      significantly modified upon polymerization to the melanin pigment. Furthermore, 
      in comparing embryonic differences, the absorption coefficients of melanosomes 
      isolated from bovine retinal pigment epithelial (RPE) cells (originating from the 
      primitive forebrain) were greater than those for bovine choroid or iris 
      melanosomes (originating from the neural crest). This difference suggests that 
      either the pigment is present in greater density in RPE melanosomes or that there 
      is an underlying difference in molecular structure.
FAU - Peles, Dana N
AU  - Peles DN
AD  - Department of Chemistry, Duke University, Durham, North Carolina 27708, United 
      States.
FAU - Simon, John D
AU  - Simon JD
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20111010
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 12627-86-0 (eumelanin)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Absorption
MH  - Animals
MH  - Cattle
MH  - Choroid/metabolism
MH  - Indoles/*chemistry
MH  - Iris/metabolism
MH  - Melanins/chemistry
MH  - Melanosomes/*chemistry
MH  - Retinal Pigment Epithelium/metabolism
MH  - Spectrophotometry, Ultraviolet
EDAT- 2011/09/20 06:00
MHDA- 2012/03/16 06:00
CRDT- 2011/09/20 06:00
PHST- 2011/09/20 06:00 [entrez]
PHST- 2011/09/20 06:00 [pubmed]
PHST- 2012/03/16 06:00 [medline]
AID - 10.1021/jp2060624 [doi]
PST - ppublish
SO  - J Phys Chem B. 2011 Nov 3;115(43):12624-31. doi: 10.1021/jp2060624. Epub 2011 Oct 
      10.