PMID- 11006597
OWN - NLM
STAT- MEDLINE
DCOM- 20001019
LR  - 20131121
IS  - 0951-4198 (Print)
IS  - 0951-4198 (Linking)
VI  - 14
IP  - 19
DP  - 2000
TI  - Effects of ultraviolet irradiation on melanogenesis from tyrosine, Dopa and 
      dopamine: a matrix-assisted laser desorption/ionization mass spectrometric study.
PG  - 1862-8
AB  - Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry experiments 
      were applied to study the influence of ultraviolet (UV) irradiation in 
      melanogenesis. Samples were prepared starting from three different precursors, 
      tyrosine, Dopa and dopamine, in the presence or absence of tyrosinase, the enzyme 
      responsible for the synthesis of melanin. Enzymatic reactions were carried out 
      for 10, 30, 60 and 120 min under UV irradiation at 365 nm, and aliquots were then 
      immediately ultrafiltered and lyophilized. Samples obtained by irradiation of 
      tyrosine solution revealed the formation of 5,6-dihydroxyindole (DHI) oligomers 
      up to pentamers at 120 min; the reaction kinetics were markedly enhanced in the 
      presence of tyrosinase. In the case of Dopa, UV irradiation favored melanogenesis 
      only in the presence of the enzyme; in this case, many reaction pathways were 
      activated, originating various oligomeric species of Dopa, DHI and 
      5,6-dihydroxyindole-2-carboxylic acid (DHICA). Conversely, when dopamine was used 
      as tyrosinase substrate under UV light, mechanisms of melanogenesis different 
      from those generated by simple enzymatic reaction without irradiation were not 
      activated, as the same oligomeric species were present.
CI  - Copyright 2000 John Wiley & Sons, Ltd.
FAU - Bertazzo, A
AU  - Bertazzo A
AD  - Dipartimento di Scienze Farmaceutiche, Via Marzolo 5, 35100 Padova, Italy.
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  - 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 (Melanins)
RN  - 42HK56048U (Tyrosine)
RN  - 63-84-3 (Dihydroxyphenylalanine)
RN  - EC 1.14.18.1 (Monophenol Monooxygenase)
RN  - VTD58H1Z2X (Dopamine)
SB  - IM
MH  - Dihydroxyphenylalanine/*chemistry/*radiation effects
MH  - Dopamine/*chemistry/*radiation effects
MH  - Melanins/*chemistry/*radiation effects
MH  - Monophenol Monooxygenase/chemistry
MH  - Photochemistry
MH  - Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
MH  - Tyrosine/*chemistry/*radiation effects
MH  - Ultraviolet Rays
EDAT- 2000/09/28 11:00
MHDA- 2000/10/21 11:01
CRDT- 2000/09/28 11:00
PHST- 2000/09/28 11:00 [pubmed]
PHST- 2000/10/21 11:01 [medline]
PHST- 2000/09/28 11:00 [entrez]
AID - 10.1002/1097-0231(20001015)14:19<1862::AID-RCM87>3.0.CO;2-U [pii]
AID - 10.1002/1097-0231(20001015)14:19<1862::AID-RCM87>3.0.CO;2-U [doi]
PST - ppublish
SO  - Rapid Commun Mass Spectrom. 2000;14(19):1862-8. doi: 
      10.1002/1097-0231(20001015)14:19<1862::AID-RCM87>3.0.CO;2-U.