The long and successful journey of electrochemically active amino acids. From fundamental adsorption studies to potential surface engineering tools.

Author(s)

ANDRÉ H.B. DOURADO ^[1] ; FABIÁN C. PASTRIÁN ^[2] ; SUSANA I. CÓRDOBA DE TORRESI ^[3]

Affiliation

^[1] Universidade de São Paulo. Instituto de Química - Brasil

^[2] Universidade de São Paulo. Instituto de Química - Brasil

^[3] Universidade de São Paulo. Instituto de Química - Brasil

• Document type: Journal article
• Source: Anais da Academia Brasileira de Ciências; v. 90, n. 1, p. 607-630, 2018-01-11.

Abstract

ABSTRACT Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His), L-Methionine (L-Met) and L-Cysteine (L-Cys); their electrochemical behavior being subject of extensive research, but it is still controversial. No spectroscopic investigations have been reported on L-Trp, and due to the short life time of the intermediates, ex situ techniques cannot be employed, leading to a never-ending discussion about possible intermediates. In the L-Tyr and L-His cases, spectroelectrochemical studies were performed and different intermediates were observed, suggesting that some intermediates may be observed under specific conditions, as proposed for L-Cys. This amino acid is the most interesting among the electroactive ones because of the presence of a thiol moiety at its side chain, leading to a wide range of oxidation states. It can adsorb onto surfaces of different crystallographic orientation in stereoselective conformation, modifying the surface for different applications.as a surface engineering tool since it plays the role of as an anchor for the growing of nanocrystals inside proteic templates. (AU)

• FAPESP's process: 13/25592-8 - Study of L-cysteine and L-cystine adsorption on platinum electrodes
• Grantee: André Henrique Baraldi Dourado
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants