PMID- 11404842
OWN - NLM
STAT- MEDLINE
DCOM- 20010809
LR  - 20181130
IS  - 0951-4198 (Print)
IS  - 0951-4198 (Linking)
VI  - 15
IP  - 13
DP  - 2001
TI  - Melanogenesis by tyrosinase action on 3,4-dihydroxyphenylalanine (DOPA) in the 
      presence of polyethylene glycol: a matrix-assisted laser desorption/ionization 
      mass spectrometric investigation.
PG  - 1061-7
AB  - The enzymatic reaction between DOPA and tyrosinase, the enzyme considered to be 
      responsible for melanogenesis, was carried out in the presence of polyethylene 
      glycol (PEG). This choice was made in order to increase the solubility of 
      melanins, since these polymers are highly insoluble. The reaction mixtures were 
      sampled at different times, immediately ultrafiltered to remove the enzyme, 
      lyophilized, and analyzed by matrix-assisted laser desorption/ionization (MALDI) 
      mass spectrometry. The results were very different from those obtained in the 
      absence of PEG. Only a few oligomers of dihydroxyindole (DHI) and 
      dihydroxyindole-2-carboxylic acid (DHICA) were detected in low abundances, 
      whereas new species originating from reaction of PEG with species belonging to 
      the Raper-Mason pattern appeared. The results show that, in the presence of PEG, 
      tyrosinase-catalyzed oligomerization of DOPA exhibits kinetics slower than those 
      observed in the absence of the polymer. However, melanogenesis still takes place 
      in the presence of PEG, as indicated by the formation of black pigments and by 
      the detection of DHI and DHICA oligomers, considered to be the first 
      intermediates in melanin formation.
CI  - Copyright 2001 John Wiley & Sons, Ltd.
FAU - Bertazzo, A
AU  - Bertazzo A
AD  - Dipartimento di Scienze Farmaceutiche, Universita di Padova, Via Marzolo 5, 35100 
      Padua, Italy.
FAU - Vogliardi, S
AU  - Vogliardi S
FAU - Favretto, D
AU  - Favretto D
FAU - Costa, C V
AU  - Costa CV
FAU - Allegri, G
AU  - Allegri G
FAU - Traldi, P
AU  - Traldi P
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Rapid Commun Mass Spectrom
JT  - Rapid communications in mass spectrometry : RCM
JID - 8802365
RN  - 0 (Indoles)
RN  - 3WJQ0SDW1A (Polyethylene Glycols)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - 63-84-3 (Dihydroxyphenylalanine)
RN  - EC 1.14.18.1 (Monophenol Monooxygenase)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Agaricales/enzymology
MH  - Dihydroxyphenylalanine/chemistry/*metabolism
MH  - Indoles/analysis/chemistry
MH  - Kinetics
MH  - Molecular Structure
MH  - Monophenol Monooxygenase/*metabolism
MH  - Polyethylene Glycols/*pharmacology
MH  - Spectrometry, Mass, Electrospray Ionization/methods
MH  - Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
EDAT- 2001/06/19 10:00
MHDA- 2001/08/10 10:01
CRDT- 2001/06/19 10:00
PHST- 2001/06/19 10:00 [pubmed]
PHST- 2001/08/10 10:01 [medline]
PHST- 2001/06/19 10:00 [entrez]
AID - 10.1002/rcm.339 [doi]
PST - ppublish
SO  - Rapid Commun Mass Spectrom. 2001;15(13):1061-7. doi: 10.1002/rcm.339.