Zika virus proteins at an atomic scale: how does structural biology help us to understand and develop vaccines and drugs against Zika virus infection?

In Brazil and in other tropical areas Zika virus infection was directly associated with clinical complications as microcephaly in newborn children whose mothers were infected during pregnancy and the Guillain-Barré syndrome in adults. Recently, research has been focused on developing new vaccines and drug candidates against Zika virus infection since none of those are available. In order to contribute to vaccine and drug development efforts, it becomes important the understanding of the molecular basis of the Zika virus recognition, infection and blockade. To this purpose, it is essential the structural determination of the Zika virus proteins. The genome sequencing of the Zika virus identified ten proteins, being three structural (protein E, protein C and protein prM) and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5). Together, these proteins are the main targets for drugs and antibody recognition. Here we examine new discoveries on high-resolution structural biology of Zika virus, observing the interactions and functions of its proteins identified via state-of-art structural methodologies as X-ray crystallography, nuclear magnetic resonance spectroscopy and cryogenic electronic microscopy. The aim of the present study is to contribute to the understanding of the structural basis of Zika virus infection at an atomic level and to point out similarities and differences to others flaviviruses.(AU)

Evaluation of inhibitory activity, purification and X-ray crystallography of Alpha-Amylase inhibitor from Phaseolus vulgaris cultivars of Uttarakhand, India / Avaliação da atividade inibitória, purificação e cristalografia de raios X do inibidor Alfa-Amilase de cultivares de Phaseolus vulgaris de Uttarakhand, Índia

Abstract The present work is based on analysis of inhibitory activity of alpha-amylase inhibitor in selected cultivars of Phaseolus vulgaris of Uttarakhand. Fifteen samples were assessed for inhibitory activity of alpha-amylase inhibitor. Significant variations were found in different cultivars. Crude extract of alpha-amylase inhibitor from sample PUR (Purola) have shown maximum inhibitory activity (70.2 ± 0.84). Crude extract of all the cultivars have shown considerable variations in inhibitory activity in the temperature ranging from 20ºC to 100ºC. Based on inhibitory activity and heat stability profile, the alpha amylase inhibitor was purified from PUR cultivar. The purified inhibitor was found to be stable even at 90ºC with an inhibitory activity of 97.20 ±0.09. The molecular weight of purified inhibitor on Native PAGE (Polyacrylamide gel electrophoresis) was found to be 31kd, consisting of two subunits of 17kd and 14kd on SDS-PAGE.

O presente trabalho é fundamentado na análise da atividade inibitória do inibidor da alfa-amilase em cultivares selecionadas de Phaseolus vulgaris, de Uttarakhand. Quinze amostras foram avaliadas quanto à atividade inibitória do inibidor da alfa-amilase. Variações significativas foram encontradas em diferentes cultivares. O extrato bruto do inibidor da alfa-amilase da amostra PUR (Purola) apresentou atividade inibitória máxima (70,2 ± 0,84). O extrato bruto de todas as cultivares apresentou variações consideráveis ​​na atividade inibitória na temperatura de 20ºC a 100ºC. Com base na atividade inibitória e no perfil de estabilidade ao calor, o inibidor da alfa-amilase foi purificado do cultivar PUR. O inibidor purificado mostrou-se estável mesmo a 90ºC, com uma atividade inibitória de 97,20 ± 0,09. O peso molecular do inibidor purificado em Native PAGE (eletroforese em gel de poliacrilamida) foi de 31kd, consistindo em duas subunidades de 17kd e 14kd em SDS-PAGE.