The effects of photodynamic treatment with new methylene blue N on the Candida albicans proteome.
Candida albicans is a human pathogenic fungus mainly affecting immunocompromised patients. Resistance to the commonly used fungicides can lead to poor treatment of mucosal infections which, in turn, can result in life-threatening systemic candidiasis. In this scenario, antimicrobial photodynamic treatment (PDT) has emerged as an effective alternative to treat superficial and localized fungal infections. Microbial death in PDT is a consequence of the oxidation of many cellular biomolecules, including proteins. Here, we report a combination of two-dimensional electrophoresis and tandem mass spectrometry to study the protein damage resulting from treating C. albicans with PDT with new methylene blue N and red light. Two-dimensional gels of treated cells showed an increase in acidic spots in a fluence-dependent manner. Amino acid analysis revealed a decrease in the histidine content after PDT, which is one plausible explanation for the observed acidic shift. However, some protein spots remained unchanged. Protein identification by mass spectrometry revealed that both modified and unmodified proteins could be localized to the cytoplasm, ruling out subcellular location as the only explanation for damage selectivity. Therefore, we hypothesize that protein modification by PDT is a consequence of both photosensitizer binding affinity and the degree of exposure of the photooxidizable residues on the protein surface.
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. guilherme.brancini@usp.br braga.br@gmail.com mariana.slrambaldi@gmail.com ayatsuda@fcfrp.usp.br gbraga@fcfrp.usp.br.
Guilherme Thomaz Pereira
http://orcid.org/0000-0001-9726-6056
GT
Brancini
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. guilherme.brancini@usp.br braga.br@gmail.com mariana.slrambaldi@gmail.com ayatsuda@fcfrp.usp.br gbraga@fcfrp.usp.br.
Gabriela Braga
GB
Rodrigues
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. guilherme.brancini@usp.br braga.br@gmail.com mariana.slrambaldi@gmail.com ayatsuda@fcfrp.usp.br gbraga@fcfrp.usp.br.
Mariana de Souza Lima
MS
Rambaldi
Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. cizumi@fmrp.usp.br jcrosa@fmrp.usp.br.
Clarice
C
Izumi
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. guilherme.brancini@usp.br braga.br@gmail.com mariana.slrambaldi@gmail.com ayatsuda@fcfrp.usp.br gbraga@fcfrp.usp.br.
Ana Patrícia
AP
Yatsuda
School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK. mark_wainwright@hotmail.com.
Mark
M
Wainwright
Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. cizumi@fmrp.usp.br jcrosa@fmrp.usp.br.
José César
JC
Rosa
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. guilherme.brancini@usp.br braga.br@gmail.com mariana.slrambaldi@gmail.com ayatsuda@fcfrp.usp.br gbraga@fcfrp.usp.br.
Gilberto Úbida Leite
GÚ
Braga
D002176:Candida albicans / Q000187:drug effects / Q000528:radiation effects; D002177:Candidiasis / Q000628:therapy*; D006801:Humans; D008027:Light; D008751:Methylene Blue / Q000031:analogs & derivatives* / Q000494:pharmacology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology; D020543:Proteome / Q000187:drug effects* / Q000528:radiation effects*
D017319:Photosensitizing Agents; D020543:Proteome; C035184:new methylene blue; D008751:Methylene Blue