Protein chemical score assay

Values for a test protein will be lower than for the reference protein. The reliability of results for chemical scoring methods depends upon the accuracy of the amino acid determinations that form the basis for these assays. Chemical scoring and animal bioassays tend to provide similar relative rankings of protein quality however, the actual values may be different. Chemical scoring methods should not replace a bioassay for testing the quality of a food protein for which there is very little nutritional information. 

Proteins have different biological availabilities in the human body and a number of methods have been introduced to evaluate and measure protein utilisation and retention. Two types of measurements are used to estimate protein quality biological assays and chemical analysis. The most common measures of protein quality included Biological Value (BV), Protein Efficiency Ratio (PER), Net Protein Utilisation (NPU), Amino Acid Score (AAS also known as chemical score, CS), Essential Amino Acid Index (EAAl) and Protein Digestibility Corrected Amino Acids Score (PDCAAS), amongst other procedures and modifications. 

This method, proposed by Satterlee represents a modification of the chemical score technique. Amino acid analysis is used to determine the essential amino acid profile and an in-vitro proteolytic enzyme step estimates the overall digestibility of the test protein. The in-vitro protein digestibility data, together with the essential amino acid profile, are then used to predict the PER (c-PER). The results obtained so far indicate a good correspondence between the calculated PERs and the actual PERs in the rat assay. The c-PER value is thus an estimate of nutritive value, with correction of the chemical score for digestibility, but it is not a measure of amino acid availability. 

Triciribine, also known as Akt/protein kinase B signaling inhibitor-2 (API-2) compound 52, Fig. 9), was identified by screening the National Cancer Institute Diversity Set chemical library (1992 compounds). The screen was performed using a cell-based proliferation assay with PKB/1 transformed NIH3T3 cells, and triciribine scored positive in this assay with an IC50 value of 50 nM [ 196]. Although the compound blocks the cellular phosphorylation... 

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