Proteínas: uma revisão e estudo de caso

Abstract

In this course conclusion work, a comprehensive review was conducted on proteins, exploring their fundamental functions, and methodologies for identification and quantification. Proteins, indispensable biomolecules, are intricate structures composed of amino acids connected by peptide bonds, organized into polypeptides. While dietary intake is a crucial source for obtaining proteins, certain organisms may not provide essential proteins, and dietary intake alone may be insufficient to meet the body's requirements, necessitating supplementation.

This study delves into the challenges associated with protein isolation and analysis, particularly focusing on methodologies for determining total protein concentration. Various UV-Vis spectrophotometric approaches, including biuret, Lowry, Bradford, and BCA methods, were examined, highlighting their applications in diverse environments such as blood plasma and nutrients. Notably, the Bradford method, utilizing Coomassie G-250, emerged as exceptional, demonstrating versatility in multiple media, including its successful application in a case study involving sports supplements.

The evolution of mass spectrometry, coupled with techniques like electrospray ionization and MALDI, was explored, showcasing their pivotal role in advancing protein analysis. The study also underscores the significance of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) as a valuable tool in proteomic analyses.

The research extends further by introducing a novel protocol that employs the Bradford colorimetric method and digital image acquisition via a cell phone camera to determine total soluble proteins in sports supplement samples. Utilizing the PhotoMetrix application for enhanced image processing, the method demonstrated a remarkable 15-fold improvement in the limit of quantification compared to spectrophotometer results. Recovery experiments yielded overwhelmingly positive results (82-112%), validated against the reference spectrophotometric method.

The proposed method proves to be portable, sensitive, accurate, and precise, presenting a valuable tool for assessing the quality of sports supplements and ensuring food safety for consumers. The study also highlights the potential of the PhotoMetrix application in advancing (bio)analytical methods.