The structural complexity of pyomelanin impacts UV shielding in Pseudomonas species with different lifestyles

Pyomelanin, a polymeric pigment in Pseudomonas, arises mainly from alterations in tyrosine degradation. The chemical structure of pyomelanin remains elusive due to its heterogeneous nature. Here, we report strain‐specific differences in pyomelanin structural features across Pseudomonas using PAO1 an...

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Bibliographic Details
Published in:	FEBS letters Vol. 598; no. 21; pp. 2702 - 2716
Main Authors:	Diaz Appella, Mateo N., Kolender, Adriana, Oppezzo, Oscar J., López, Nancy I., Tribelli, Paula M.
Format:	Journal Article
Language:	English
Published:	England 01-11-2024
Subjects:	melanin Pseudomonas structure UVC resistance UVC resistance Pseudomonas melanin structure
Online Access:	Get full text
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Summary:	Pyomelanin, a polymeric pigment in Pseudomonas, arises mainly from alterations in tyrosine degradation. The chemical structure of pyomelanin remains elusive due to its heterogeneous nature. Here, we report strain‐specific differences in pyomelanin structural features across Pseudomonas using PAO1 and PA14 reference strains carrying mutations in hmgA (a gene involved in pyomelanin synthesis), a melanogenic P. aeruginosa clinical isolate (PAM), and a melanogenic P. extremaustralis (PexM). UV spectra showed dual peaks for PAO1 and PA14 mutants and single peaks for PAM and PexM. FTIR phenol : alcohol ratio changes and complex NMR spectra indicated non‐linear polymers. UVC radiation survival increased with pyomelanin addition, correlating with pigment absorption attenuation. P. extremaustralis UVC survival varied with melanin source, with PAO1 pyomelanin being the most protective. These findings delineate structure‐based pyomelanin subgroups, having distinct physiological effects. We identify structure‐based pyomelanin subgroups within the same bacterial genus, showing that strain‐specific differences in the structural features of pyomelanin across Pseudomonas impact on their capability to survive under UVC radiation. Melanin from different strains exhibits different protective effects due to variations in pigment absorption.
Bibliography:	Mateo N. Diaz Appella and Adriana Kolender contributed equally to this article. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0014-5793 1873-3468 1873-3468
DOI:	10.1002/1873-3468.15000