Question

Explain the advantage of using protein determination in the context of modern biotechnology. Support your explanation with a current concrete example.

Answer 1

Proteins have a major role in the growth and maintenance of the human body and are, along with carbohydrates and lipids, the energy giving nutrients in the diet. In addition, proteins also pose a wide range of other functions in the body, such as enzymatic activity and transport of nutrients and other biochemical compounds across cellular membranes [1]. In order to maintain these important functions, it is essential to provide the body with good quality proteins through diet. Inadequate intake of dietary proteins containing essential amino acids results in increased turnover of muscular proteins, leading to reduced growth and loss of muscle mass. Impaired immunity, as well as reduced hormonal and enzymatic activity may subsequently follow . Being such important constituents of human diet it is crucial to know the protein content in foods and thus it is important to have reliable analytical methods.

Composition, food structure, or matrix, and interactions between the different nutrients may reduce the accessibility of the proteins leading to underestimation of the protein content. In addition, different methods are based on different analytical principles, determining protein content either directly or indirectly. Direct protein determination is when protein content is calculated based on the analysis of amino acid residues. Indirect protein determination can for instance be inferred following the determination of the nitrogen content, or after chemical reactions with functional groups within the protein.

Protein quantification or total protein content by colorimetric methods such as absorbance at 280, Bradford or BCA assays and quantitative amino acid analysis...

Protein quantification is necessary to understand the total protein content in a sample or in a formulated product. Accurate protein quantification is important as a range of other critical assays require precise total protein content results in order to generate data. Careful selection of the protein quantification method is required to ensure accurate data. Colorimetric assays, for example, are dependent on the use of an external reference standard and the different absorbance properties between product and the reference standard may lead to inaccuracies. Quantitative amino acid analysis can also be used for protein content determination but an understanding of how different proteins hydrolyze under similar conditions and the stability of amino acids during hydrolysis is critical.