An engineered SARS-CoV-2 receptor-binding domain produced in Pichia pastoris as a candidate vaccine antigen.

Developing affordable and easily manufactured SARS-CoV-2 vaccines will be essential to achieve worldwide vaccine coverage and long-term control of the COVID-19 pandemic. Here the development is reported of a vaccine based on the SARS-CoV-2 receptor-binding domain (RBD), produced in the yeast Pichia pastoris. The RBD was modified by adding flexible N- and C-terminal amino acid extensions that modulate protein/protein interactions and facilitate protein purification. A fed-batch methanol fermentation with a yeast extract-based culture medium in a 50 L fermenter and an immobilized metal ion affinity chromatography-based downstream purification process yielded 30-40 mg/L of RBD. Correct folding of the purified protein was demonstrated by mass spectrometry, circular dichroism, and determinations of binding affinity to the angiotensin-converting enzyme 2 (ACE2) receptor. The RBD antigen also exhibited high reactivity with sera from convalescent individuals and Pfizer-BioNTech or Sputnik V vaccinees. Immunization of mice and non-human primates with 50 µg of the recombinant RBD adjuvanted with alum induced high levels of binding antibodies as assessed by ELISA with RBD produced in HEK293T cells, and which inhibited RBD binding to ACE2 and neutralized infection of VeroE6 cells by SARS-CoV-2. Additionally, the RBD protein stimulated IFNγ, IL-2, IL-6, IL-4 and TNFα secretion in splenocytes and lung CD3+-enriched cells of immunized mice. The data suggest that the RBD recombinant protein produced in yeast P. pastoris is suitable as a vaccine candidate against COVID-19.

Manual mass spectrometry de novo sequencing of the anionic host defense peptides of the Cuban Treefrog Osteopilus septentrionalis.

RATIONALE: Host defense peptides accumulated in the skin glands of the animals constitute the basis of the adaptive and immune system of amphibians. The peptidome of the Cuban frog Osteopilus septentrionalis was established using tandem mass spectrometry as the best analytical tool to elucidate the sequence of these peptides. METHODS: Manual interpretation of complementary collision-induced dissociation (CID), higher energy collision-induced dissociation (HCD), and electron transfer dissociation (ETD) tandem mass spectra recorded with an Orbitrap Elite mass spectrometer in liquid chromatography/mass spectrometry (LC/MS) mode was used to sequence the peptide components of the frog skin secretion, obtained by mild electrostimulation. RESULTS: Although the vast majority of amphibian peptides discovered so far are cationic, surprisingly only anionic peptides were identified in the skin secretion of the Cuban frog Osteopilus septentrionalis. Mass spectrometry allowed the sequences to be established of 16 representatives of new peptide families: septenins 1 and septenins 2. The highest sequence coverage when dealing with these anionic peptides was obtained with CID normalized collision energy 35 and HCD normalized collision energy 28. CONCLUSIONS: Mirror-symmetrical peptides are sequenced using N-terminal acetylation. Acetylated Ser is reliably distinguished from isomeric Glu by the loss of ketene from b-ions containing the corresponding residue. Calculations of the physicochemical and structural properties of the discovered anionic septenins 1 and 2 allowed the mechanism of their interaction with microbe cells to be postulated.

Calificación de un cromatógrafo de gases Agilent Technologies 7890A utilizado en la industria biotecnológica / Qualification of an Agilent Technologies 7890A gas chromatograph used in the biotechnology industry

INTRODUCCIÓN: la producción de medicamentos se rige por estrictas normas internacionales que garantizan la reproducibilidad y consistencia de los resultados obtenidos. La calificación de los instrumentos utilizados en los procesos productivos, así como en la caracterización de los productos y su control de calidad, constituye un requisito previo a la validación de cualquier técnica analítica que haga uso de estos. Una de las técnicas instrumentales utilizada en la industria biotecnológica es la cromatografía de gases. OBJETIVO: desarrollar y ejecutar un protocolo que permita la calificación de un cromatógrafo de gases Agilent Technologies 7890A. MÉTODOS: se empleó un patrón de cafeína pura para análisis y se utilizó una columna HP-5 de 30 m x 0,32 mm d.i. y 0,33 µm espesor de película, en un cromatógrafo de gases acoplado a un detector de ionización de llama. Los diferentes módulos involucrados en el análisis (inyector, columna, horno y detector) se evaluaron a través de un diseño experimental que calcula varios parámetros. RESULTADOS: se obtuvieron pruebas documentadas que demuestran que cada uno de los parámetros estudiados (linealidad del inyector, precisión del inyector, arrastre del inyector, precisión del flujo, exactitud del flujo, linealidad del detector, exactitud del detector, ruido del detector, deriva del detector) cumple con los criterios de aceptación establecidos. CONCLUSIONES: el protocolo desarrollado permite la calificación de un cromatógrafo de gases Agilent Technologies 7890A y puede ser extrapolado a otros modelos(AU)

INTRODUCTION: the drug manufacture is governed by strict international standards that guarantee reproducibility and consistency of results. The qualification of the instruments used in the productive processes, as well as in the characterization of products and their quality control are prerequisites to the validation of any analytical technique using them. One of the instrumental techniques used in the biotechnical industry is Gas Chromatography. OBJECTIVE: to develop and to perform a protocol that allows the qualification of an Agilent Technologies 7890A Gas Chromatograph. METHODS: a standard of pure caffeine was used for analysis in addition to a HP-5 30 m x 0,32 mm d.i. and 0,33 µm thick film column was used in a Gas Chromatograph coupled with a Flame Ionization Detector. For the testing of the different modules involved in the analysis (injector, column, oven and detector), an experimental design was made to estimate several parameters. RESULTS: the obtained documented tests proved that each of the studied parameters (injector linearity, injector precision, injector dragging, flow precision, flow accuracy, detector linearity, detector accuracy, detector noise and detector drift) met the set acceptance criteria. CONCLUSIONS: the final protocol allows the qualification of an Agilent Technologies 7890A Gas Chromatograph and it can be extrapolated to other models(AU)

Calificación de un cromatógrafo de gases Agilent Technologies 7890A utilizado en la industria biotecnológica / Qualification of an Agilent Technologies 7890A gas chromatograph used in the biotechnology industry

Introducción: la producción de medicamentos se rige por estrictas normas internacionales que garantizan la reproducibilidad y consistencia de los resultados obtenidos. La calificación de los instrumentos utilizados en los procesos productivos, así como en la caracterización de los productos y su control de calidad, constituye un requisito previo a la validación de cualquier técnica analítica que haga uso de estos. Una de las técnicas instrumentales utilizada en la industria biotecnológica es la cromatografía de gases. Objetivo: desarrollar y ejecutar un protocolo que permita la calificación de un cromatógrafo de gases Agilent Technologies 7890A. Métodos: se empleó un patrón de cafeína pura para análisis y se utilizó una columna HP-5 de 30 m x 0,32 mm d.i. y 0,33 µm espesor de película, en un cromatógrafo de gases acoplado a un detector de ionización de llama. Los diferentes módulos involucrados en el análisis (inyector, columna, horno y detector) se evaluaron a través de un diseño experimental que calcula varios parámetros. Resultados: se obtuvieron pruebas documentadas que demuestran que cada uno de los parámetros estudiados (linealidad del inyector, precisión del inyector, arrastre del inyector, precisión del flujo, exactitud del flujo, linealidad del detector, exactitud del detector, ruido del detector, deriva del detector) cumple con los criterios de aceptación establecidos. Conclusiones: el protocolo desarrollado permite la calificación de un cromatógrafo de gases Agilent Technologies 7890A y puede ser extrapolado a otros modelos(AU)

Introduction: the drug manufacture is governed by strict international standards that guarantee reproducibility and consistency of results. The qualification of the instruments used in the productive processes, as well as in the characterization of products and their quality control are prerequisites to the validation of any analytical technique using them. One of the instrumental techniques used in the biotechnical industry is Gas Chromatography. Objective: to develop and to perform a protocol that allows the qualification of an Agilent Technologies 7890A Gas Chromatograph. Methods: a standard of pure caffeine was used for analysis in addition to a HP-5 30 m x 0,32 mm d.i. and 0,33 Ám thick film column was used in a Gas Chromatograph coupled with a Flame Ionization Detector. For the testing of the different modules involved in the analysis (injector, column, oven and detector), an experimental design was made to estimate several parameters. Results: the obtained documented tests proved that each of the studied parameters (injector linearity, injector precision, injector dragging, flow precision, flow accuracy, detector linearity, detector accuracy, detector noise and detector drift) met the set acceptance criteria. Conclusions: the final protocol allows the qualification of an Agilent Technologies 7890A Gas Chromatograph and it can be extrapolated to other models(AU)