Protein expression regulation under oxidative stress.

Oxidative stress is known to affect both translation and protein turnover, but very few large scale studies describe protein expression under stress. We measure protein concentrations in Saccharomyces cerevisiae over the course of 2 h in response to a mild oxidative stress induced by diamide, providing detailed time-resolved information for 815 proteins, with additional data for another ~1,100 proteins. For the majority of proteins, we discover major differences between the global transcript and protein response. Although mRNA levels often return to baseline 1 h after treatment, protein concentrations continue to change. Integrating our data with features of translation and protein degradation, we are able to predict expression patterns for 41% of the proteins in the core data set. Predictive features include, among others, targeting by RNA-binding proteins (Lhp1 and Khd1), RNA secondary structures, RNA half-life, and translation efficiency under unperturbed conditions and in response to oxidative reagents, but not chaperone binding. We are able to both describe general dynamics of protein concentration changes and suggest possible regulatory mechanisms for individual proteins.

Colorectal cancer survival in Greater Cuiabá, state of Mato Grosso, Brazil. / Sobrevida do câncer colorretal na Grande Cuiabá, Mato Grosso, Brasil.

OBJECTIVE: To analyze the specific five-year survival of colorectal cancer (CRC) diagnosed between 2008 and 2013, according to sex and age group, of residents in Greater Cuiabá, state of Mato Grosso, Brazil. METHODS: This is a retrospective cohort study. Specific survival of CRC was considered as the time between disease diagnosis and death from CRC, in months. Data from the Population-Based Cancer Registry and the Brazilian Mortality Information System were used. To estimate the probability of survival by sex and age group, the Kaplan-Meier estimator was used, and to estimate the effect of age group on the survival of participants, the Cox model stratified by sex was adjusted. RESULTS: From 2008 to 2013, 683 new cases and 193 deaths from CRC were registered. The median time between diagnosis and death from CRC was 44.8 months (95%CI 42.4- 47.3) for women and 46.1 months (95%CI 43.4-48.6) for men, and the five-year survival probabilities of 83.5% (95%CI 79.9-87.2%) and 89.6% (95%CI 86.4-93.0%), respectively. Men aged 70-79 years (HR=2.97; 95%CI 1.11-3.87) and 80 years or older (HR=3.09; 95%CI 1.31-7.27) were at higher risk of mortality, and we verified no difference for women. CONCLUSION: Women had a shorter time between the diagnosis of CRC and death from the disease as well as a lower probability of survival. Conversely, men were at higher risk of mortality after 70 years of age.

OBJETIVO: Analisar a sobrevida específica em cinco anos do câncer colorretal diagnosticado entre 2008 e 2013, segundo sexo e faixa etária, de residentes na Grande Cuiabá, Mato Grosso. MÉTODOS: Estudo de coorte retrospectiva. A sobrevida específica pelo câncer colorretal foi considerada como o tempo entre o diagnóstico da doença até o óbito por câncer colorretal, em meses. Utilizaram-se dados do Registro de Câncer de Base Populacional e do Sistema de Informações sobre Mortalidade. Para estimar a probabilidade de sobrevida por sexo e faixa etária, utilizou-se o estimador de Kaplan-Meier, e, para estimar o efeito da faixa etária na sobrevida dos participantes, foi ajustado modelo de Cox estratificado por sexo. RESULTADOS: De 2008 a 2013, registraram-se 683 casos novos e 193 óbitos por câncer colorretal. O tempo mediano entre o diagnóstico e a morte por câncer colorretal foi de 44,8 meses (IC95% 42,4­47,3) para as mulheres e 46,1 meses (IC95% 43,4­48,6) para os homens e a probabilidade de sobrevida em cinco anos de 83,5% (IC95% 79,9­87,2%) e 89,6% (IC95% 86,4­93,0%), respectivamente. Os homens com 70-79 anos (HR=2,97; IC95% 1,11­3,87) e com 80 anos ou mais (HR=3,09; IC95% 1,31­7,27) apresentaram maior risco de mortalidade e sem diferença para as mulheres. CONCLUSÃO: O sexo feminino apresentou menor tempo entre o diagnóstico e o óbito pela doença, assim como menor probabilidade de sobrevida. Em contrapartida, foram os homens que apresentaram maior risco de mortalidade a partir dos 70 anos.

Effect of pH variation and crosslinker absence on the gelling mechanism of high acyl gellan: Morphological, thermal and mechanical approaches.

This article describes the preparation of superabsorbent hydrogels made of high acyl gellan without the addition of a crosslinker . Variations of the pH of the medium and different gellan solution concentrations were evaluated. The samples produced were investigated regarding their morphology by scanning electron microscopy, thermal resistance by thermogravimetry, and compressive strength by mechanical testing. Rheological tests were also performed and the swelling decree of the hydrogels was calculated. The results showed that the morphology of the samples could be modified by varying the preparation conditions, ranging from a foliaceous structure to a brittle structure, containing voids with different sizes. The hydrogels prepared with acidic pH presented less compressive strength than those prepared with basic pH. Although all the samples had swelling degree greater than 1000 %, the highest values were obtained with the samples prepared at pH 4, regardless of the concentration of the gellan solution.

Sobrevida do câncer colorretal na Grande Cuiabá, Mato Grosso, Brasil / Colorectal cancer survival in Greater Cuiabá, state of Mato Grosso, Brazil

RESUMO Objetivo: Analisar a sobrevida específica em cinco anos do câncer colorretal diagnosticado entre 2008 e 2013, segundo sexo e faixa etária, de residentes na Grande Cuiabá, Mato Grosso. Métodos: Estudo de coorte retrospectiva. A sobrevida específica pelo câncer colorretal foi considerada como o tempo entre o diagnóstico da doença até o óbito por câncer colorretal, em meses. Utilizaram-se dados do Registro de Câncer de Base Populacional e do Sistema de Informações sobre Mortalidade. Para estimar a probabilidade de sobrevida por sexo e faixa etária, utilizou-se o estimador de Kaplan-Meier, e, para estimar o efeito da faixa etária na sobrevida dos participantes, foi ajustado modelo de Cox estratificado por sexo. Resultados: De 2008 a 2013, registraram-se 683 casos novos e 193 óbitos por câncer colorretal. O tempo mediano entre o diagnóstico e a morte por câncer colorretal foi de 44,8 meses (IC95% 42,4-47,3) para as mulheres e 46,1 meses (IC95% 43,4-48,6) para os homens e a probabilidade de sobrevida em cinco anos de 83,5% (IC95% 79,9-87,2%) e 89,6% (IC95% 86,4-93,0%), respectivamente. Os homens com 70-79 anos (HR=2,97; IC95% 1,11-3,87) e com 80 anos ou mais (HR=3,09; IC95% 1,31-7,27) apresentaram maior risco de mortalidade e sem diferença para as mulheres. Conclusão: O sexo feminino apresentou menor tempo entre o diagnóstico e o óbito pela doença, assim como menor probabilidade de sobrevida. Em contrapartida, foram os homens que apresentaram maior risco de mortalidade a partir dos 70 anos.

ABSTRACT Objective: To analyze the specific five-year survival of colorectal cancer (CRC) diagnosed between 2008 and 2013, according to sex and age group, of residents in Greater Cuiabá, state of Mato Grosso, Brazil. Methods: This is a retrospective cohort study. Specific survival of CRC was considered as the time between disease diagnosis and death from CRC, in months. Data from the Population-Based Cancer Registry and the Brazilian Mortality Information System were used. To estimate the probability of survival by sex and age group, the Kaplan-Meier estimator was used, and to estimate the effect of age group on the survival of participants, the Cox model stratified by sex was adjusted. Results: From 2008 to 2013, 683 new cases and 193 deaths from CRC were registered. The median time between diagnosis and death from CRC was 44.8 months (95%CI 42.4- 47.3) for women and 46.1 months (95%CI 43.4-48.6) for men, and the five-year survival probabilities of 83.5% (95%CI 79.9-87.2%) and 89.6% (95%CI 86.4-93.0%), respectively. Men aged 70-79 years (HR=2.97; 95%CI 1.11-3.87) and 80 years or older (HR=3.09; 95%CI 1.31-7.27) were at higher risk of mortality, and we verified no difference for women. Conclusion: Women had a shorter time between the diagnosis of CRC and death from the disease as well as a lower probability of survival. Conversely, men were at higher risk of mortality after 70 years of age.

Evaluation of different methods to prepare superabsorbent hydrogels based on deacetylated gellan.

This study stands out for analyzing distinct ways of preparing hydrogels from deacetylated gellan gum that have high swelling capacity and good thermal resistance. We carried out a thorough investigation, applying various combinations of different experimental parameters. Two preparation methods were evaluated, in which the pH was adjusted before or after thermal treatment of the gellan solution, with subsequent addition of the crosslinking agent, to assess the influence of preparation method on the conformation of the gellan chains regarding formation of double helices. The pH range tested varied from acid (2, 3 or 4) to basic (8, 9 or 10). Gellan solution was prepared in different concentrations. Both pure gellan and hydrogel samples were characterized by Fourier-transform infrared spectroscopy and thermogravimetry. Pure gellan was also characterized by atomic absorption spectroscopy. The swelling degree of the hydrogels was analyzed. The results showed that all the hydrogels had high swelling capacity (>400%), so they can be considered superabsorbent materials. Hydrogels prepared with acid pH in general had lower thermal resistance than samples prepared in alkaline pH, regardless of the preparation method. Samples prepared with alkaline pH tended to have initial decomposition temperature similar to that of pure gellan.

Crystallization and preliminary X-ray crystallographic studies of glutaredoxin 2 from Saccharomyces cerevisiae in different oxidation states.

Glutaredoxins are small (9-12 kDa) heat-stable proteins that are highly conserved throughout evolution; the glutaredoxin active site (Cys-Pro-Tyr-Cys) is conserved in most species. Five glutaredoxin genes have been identified in Saccharomyces cerevisiae; however, Grx2 is responsible for the majority of oxidoreductase activity in the cell, suggesting that its primary function may be the detoxification of mixed disulfides generated by reactive oxygen species (ROS). Recombinant Grx2 was expressed in Escherichia coli as a 6xHis-tagged fusion protein and purified by nickel-affinity chromatography. Prior to crystallization trials, the enzyme was submitted to various treatments with reducing agents and peroxides. Crystals suitable for X-ray diffraction experiments were obtained from untreated protein and protein oxidized with t-butyl hydroperoxide (10 mM). Complete data sets were collected to resolutions 2.15 and 2.05 A for untreated and oxidized Grx2, respectively, using a synchrotron-radiation source. The crystals belong to space group P4(1)2(1)2, with similar unit-cell parameters.

Mass spectrometry analysis of K63-ubiquitinated targets in response to oxidative stress.

The data described here provide the first large-scale analysis of lysine 63 (K63)-linked polyubiquitin targets. Protein ubiquitination is a prominent post-translational modification, and a variety of ubiquitin chains exists, serving a multitude of functions [1]. The chains differ by the lysine residue by which the ubiquitin monomers are linked. We used yeast Saccharomyces cerevisiae subjected to oxidative stress as a model to study K63 ubiquitination. K63 ubiquitinated targets were pulled-down by the K63-TUBE system (Tandem Ubiquitin Binding Entities) and analyzed by SILAC-based mass spectrometry [2]. The data are associated to the research article 'K63 polyubiquitination is a new modulator of the oxidative stress response' [3]. The mass spectrometry and the analysis dataset have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the dataset identifier PXD000960.

Qualidade higiênico-sanitária e pesquisa de coliformes totais e fecais no caldo de cana (garapa), consumido no município de Cacoal-RO / Hygienic-sanitary quality and research of total and final coliforms in the cane juice (garapa), consumed in the city of Cacoal-RO

O objetivo neste trabalho foi analisar amostras de caldo de cana, provenientes de Cacoal-RO, a fim de identificar a possível presença de coliformes totais e termotolerantes, podendo assim comparar com a legislação vigente e caracterizar como adequado ou não para o consumo humano; além disso, foram observadas a higiene dos manipuladores, equipamentos e carrinhos utilizados na comercialização do produto. Foram analisadas vinte amostras seguindo os critérios de analise microbiológica dos tubos múltiplos, no qual os tubos onde a amostra apresentava produção de gás eram considerados como resultado positivo. Os resultados foram positivos para todas as amostras (100% apresentaram valores de coliformes a 45ºC em torno de >1100 NMP/mL) e ao observar as condições higiênico-sanitárias apresentaram muitos pontos negativos, entre os quais: alto percentual de vendedores que não utilizava proteção para os cabelos (100%) e luvas (100%) e grande parte utilizava adornos (80%). Podemos concluir que o principal motivo para que esse alimento apresentasse um resultado unânime positivo foi a higiene incorreta dos manipuladores, provocando contaminação no momento da manipulação.(AU)

Análise bromatológica da castanha-do-Maranhão (Bombacopsis glabra) / Bromatological analysis of castanha-do-Maranhão (Bombacopsis glabra)

A castanha-do-Maranhão (Bombacopsis glabra) é uma espécie ornamental arbórea, com sementes oleaginosas (amêndoas) comestíveis e popularmente apreciadas no interior do Maranhão. O objetivo do trabalho foi elaborar a composição centesimal das amêndoas. As análises de umidade, cinzas, proteínas, lipídeos e carboidratos foram feitas em triplicata e consoantes às Normas do Instituto Adolfo Lutz (2010). Estimou-se além do valor calórico das amêndoas os seguintes valores médios (g/100g): umidade 2,85±0,09; cinzas, 4,80±0,08; proteínas 10,20±0,07; lipídeos 52,40±0,08 e carboidratos 29,70±0,07. O valor energético foi de 631,20±0,06 Kcal/100g. Constatou-se que as sementes da castanha-do-Maranhão possuem um relevante valor calórico, quando comparada com outras oleaginosas, podendo ser utilizada pela população como suplemento na alimentação.(AU)

Análise bromatológica da castanha-do-Maranhão (Bombacopsis glabra) / Bromatological analysis of castanha-do-Maranhão (Bombacopsis glabra)

A castanha-do-Maranhão (Bombacopsis glabra) é uma espécie ornamental arbórea, com sementes oleaginosas (amêndoas) comestíveis e popularmente apreciadas no interior do Maranhão. O objetivo do trabalho foi elaborar a composição centesimal das amêndoas. As análises de umidade, cinzas, proteínas, lipídeos e carboidratos foram feitas em triplicata e consoantes às Normas do Instituto Adolfo Lutz (2010). Estimou-se além do valor calórico das amêndoas os seguintes valores médios (g/100g): umidade 2,85±0,09; cinzas, 4,80±0,08; proteínas 10,20±0,07; lipídeos 52,40±0,08 e carboidratos 29,70±0,07. O valor energético foi de 631,20±0,06 Kcal/100g. Constatou-se que as sementes da castanha-do-Maranhão possuem um relevante valor calórico, quando comparada com outras oleaginosas, podendo ser utilizada pela população como suplemento na alimentação.

Qualidade higiênico-sanitária e pesquisa de coliformes totais e fecais no caldo de cana (garapa), consumido no município de Cacoal-RO / Hygienic-sanitary quality and research of total and final coliforms in the cane juice (garapa), consumed in the city of Cacoal-RO

O objetivo neste trabalho foi analisar amostras de caldo de cana, provenientes de Cacoal-RO, a fim de identificar a possível presença de coliformes totais e termotolerantes, podendo assim comparar com a legislação vigente e caracterizar como adequado ou não para o consumo humano; além disso, foram observadas a higiene dos manipuladores, equipamentos e carrinhos utilizados na comercialização do produto. Foram analisadas vinte amostras seguindo os critérios de analise microbiológica dos tubos múltiplos, no qual os tubos onde a amostra apresentava produção de gás eram considerados como resultado positivo. Os resultados foram positivos para todas as amostras (100% apresentaram valores de coliformes a 45ºC em torno de >1100 NMP/mL) e ao observar as condições higiênico-sanitárias apresentaram muitos pontos negativos, entre os quais: alto percentual de vendedores que não utilizava proteção para os cabelos (100%) e luvas (100%) e grande parte utilizava adornos (80%). Podemos concluir que o principal motivo para que esse alimento apresentasse um resultado unânime positivo foi a higiene incorreta dos manipuladores, provocando contaminação no momento da manipulação.

Reactive cysteine in proteins: protein folding, antioxidant defense, redox signaling and more.

Cysteine plays structural roles in proteins and can also participate in electron transfer reactions, when some structural folds provide appropriated environments for stabilization of its sulfhydryl group in the anionic form, called thiolate (RS(-)). In contrast, sulfhydryl group of free cysteine has a relatively high pK(a) (8,5) and as a consequence is relatively inert for redox reaction in physiological conditions. Thiolate is considerable more powerful as nucleophilic agent than its protonated form, therefore, reactive cysteine are present mainly in its anionic form in proteins. In this review, we describe several processes in which reactive cysteine in proteins take part, showing a high degree of redox chemistry versatility.

20 S proteasome from Saccharomyces cerevisiae is responsive to redox modifications and is S-glutathionylated.

The 20 S proteasome core purified from Saccharomyces cerevisiae is inhibited by reduced glutathione (GSH), cysteine (Cys), or the GSH precursor gamma-glutamylcysteine. Chymotrypsin-like activity was more affected by GSH than trypsin-like activity, whereas the peptidylglutamyl-hydrolyzing activity (caspase-like) was not inhibited by GSH. Cys-sulfenic acid formation in the 20 S core was demonstrated by spectral characterization of the Cys-S(O)-4-nitrobenzo-2-oxa-1,3-diazole adduct, indicating that 20 S proteasome Cys residues might react with reduced sulfhydryls (GSH, Cys, and gamma-glutamylcysteine) through the oxidized Cys-sulfenic acid form. S-Glutahionylation of the 20 S core was demonstrated in vitro by GSH-biotin incorporation and by decreased alkylation with monobromobimane. Compounds such as N-ethylmaleimide (-S-sulfhydril H alkylating), dimedone (-SO sulfenic acid H reactant), or 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (either -SH or -SOH reactant) highly inhibited proteasomal chymotrypsin-like activity. In vivo experiments revealed that 20 S proteasome extracted from H(2)O(2)-treated cells showed decreased chymotrypsin-like activity accompanied by S-glutathionylation as demonstrated by GSH release from the 20 S core after reduction with NaBH(4). Moreover, cells pretreated with H(2)O(2) showed decreased reductive capacity assessed by determination of the GSH/oxidized glutathione ratio and increased protein carbonyl levels. The present results indicate that at the physiological level the yeast 20 S proteasome is regulated by its sulfhydryl content, thereby coupling intracellular redox signaling to proteasome-mediated proteolysis.

Qualidade físico-química de licores artesanais de jenipapo (Genipa americana L) comercializados em São Luís, MA / Physico-chemical quality of liquors jenipapo (Genipa americana L) marketed in São Luís, MA

o licor é uma bebida alcoólica obtida por mistura que se caracteriza pela elevada proporção de açúcar; sendo constituído basicamente de três ingredientes: álcool, calda de açúcar e extrato aromático. Trata-se de uma bebida que agrada aos paladares mais exigentes, sendo que os mais finos e famosos licores têm suas receitas preservadas por gerações. Nesse contexto, destaca-se o jenipapo (Genipa americana L.), que embora com vários usos na culinária indígena e como medicinal, a maior parte dos frutos é ainda comercializada para a produção caseira ou em pequenas indústrias artes anais de licor. Em São Luís-MA a tradição dos licores de jenipapo é mantida e a comercialização da bebida artesanal é muito comum. Dada a importância desse produto para os produtores locais, o presente trabalho objetivou analisar a qualidade físico-química de amostras de licores artesanais de jenipapo (quanto ao pH, acidez titulável, grau Brix, densidade, teor alcoólico e sacarose) comercializados na capital maranhense. Contudo, osresultados mostraram que as amostras analisadas estão fora do padrão exigido pela legislação brasileira(Decreto n° 6.871, de 4 de junho de I 2009 (BRASIL, 2009)). (AU)

Liquor is an alcoholic beverage obtained by the mixture that is characterized by high sugar, consistingof three basic ingredients: alcohol, sugar syrup and extract aromatic. It is a drink that tastes like the mostdemanding, and the finest liquors and famous have their recipes preserved through generations. In this context, we highlight the jenipapo fruit (Genipa americana L.), which although with many uses in cooking and as indigenous medicine, most of the fruit is still marketed for home production orin small cottage industries of liquor. In Sao Luis, Brazil tradition of jenipapo fruit liquor is kept and marketing of the drink is very common craft. Given the importance of the product to local producers, this study aimed to analyze the physical and chemical quality of samples of artisanal liquors jenipapo fruit (for pH, acidity, Brix density, alcohol content and sucrose) sold in the capital of Maranhão State. However the results showed that the samples are outside the standard required by Brazilian law Decree No. 6871 of June 4, 2009 (BRAZIL, 2009). (AU)

Determinação e avaliação da concentração de cobre em aguardentes de cana, produzidas artesanalmente nas regiões Alpercatas e Sertão Maranhense / Determination and evaluation of copper concentration in sugar cane produced regions Maranhense

O processo de fabricação de aguardentes artesanais de cana-de-açúcar no Brasil possui tecnologia precária. No Maranhão, a maioria dos destiladores empregados nos alambiques é feito de cobre, material de uso frequente, já que o produto apresenta melhor qualidade sensorial, se comparado aos alambiques confeccionados com outros materiais, como aço inox. Este trabalho teve por objetivo investigar a concentração de cobre em amostras de aguardentes produzidas em alambiques artesanais nas regiões Alpercatas e Sertão Maranhense, através da técnica de Espectrofotometria de Absorção Atômica (AOAC, 2006). Os resultados evidenciaram altos teores do metal, variando de 9,43 a 43,01 mL, estando muito acima do permitido pela legislação, que fixa limite máximo de 5 mg L.(AU)

Estudo e caracterização do processo de glutatiolação e desglutatiolação da unidade 20S do proteassomo da levedura Saccharomyces cerevisiae: Implicações na regulação do metabolismo redox intracelular e na geração de peptídeos / Study and characterization of the S-glutathiolation and deglutathiolation of the 20S proteasome core from the yeast Saccharomyces cerevisiae: Implications on the intracellular redox metabolism and peptide generation

O proteassomo é o componente do sistema Ubiquitina-Proteassomo (UPS), responsável pela degradação de proteínas intracelulares marcadas com cauda de ubiquitina. No entanto, a unidade catalítica do proteassomo (20SPT), destituída de unidades regulatórias, é capaz de degradar proteínas de maneira ubiquitina-independente. Diversas modificações pós-traducionais já foram descritas para o 20SPT, incluindo a S-glutatiolação. De acordo com Demasi e col., (2003) o 20SPT da levedura Saccharomyces cerevisiae possui a atividade tipo-quimiotripsina modulada por glutationa e o mecanismo de glutatiolação implica na formação do intermediário ácido sulfênico. No presente trabalho, identificamos por espectrometria de massas (MS/MS) um total de sete resíduos diferentes de cisteína glutatiolados no 20SPT, sendo seis in vitro por incubação com GSH e três in vivo, extraído de células crescidas até atingir fase estacionária tardia em meio rico. Analisando a estrutura 3D do 20SPT, observou-se que os resíduos de cisteína glutatiolados não estão localizados na entrada da câmara catalítica nem próximos aos sítios-ativos, indicando um mecanismo alostérico da modulação da atividade proteassomal...

The proteasome is the protease of the Ubiquitin-Proteasome System (UPS) responsible for the breakdown of intracellular ubiquitin-tagged proteins. However, the catalytic particle of the proteasome (20SPT) is capable of hydrolyzing some substrates in an ubiquitin-independent fashion. The S-glutathiolation of the 20SPT was described among several post-translational modifications and according to Demasi et. al. (2003), the chymotrypsin-like activity of proteasome from yeast Saccharomyces cerevisiae is regulated by glutathione. The mechanism of S-glutathiolation is dependent on the formation of the sulfenic acid intermediate in the cisteine residues of the 20SPT. In this present work, we identified in vitro and in vivo, a total of seven different S-glutathiolated proteasomal cysteine residues by mass spectrometry studies (MS/MS) and, by analyzing the 3D structure of the 20SPT, the modified cysteine residues are not located either on the entrance of the catalytic core or near to the active sites, indicating an allosteric mechanism of proteasomal modulation. During protein degradation, the natively S-glutathiolated 20SPT produces different patterns of peptide products when compared to the DTT-reduced particle through distinct site-specific cleavage of the protein substrates, as herein demonstrated by HPLC and MS/MS analyses...

Reactive cysteine in proteins Protein folding, antioxidant defense, redox signaling and more

Cysteine plays structural roles in proteins and can also participate in electron transfer reactions, when some structural folds provide appropriatedenvironments for stabilization of its sulfhydryl group in the anionic form, called thiolate (RS−). In contrast, sulfhydryl group of free cysteine has arelatively high pKa (8,5) and as a consequence is relatively inert for redox reaction in physiological conditions. Thiolate is considerable morepowerful as nucleophilic agent than its protonated form, therefore, reactive cysteine are present mainly in its anionic form in proteins. In this review,we describe several processes in which reactive cysteine in proteins take part, showing a high degree of redox chemistry versatility.