Testing protein functionality

Author(s):  
R Owusu-Apenten
2013 ◽  
Vol 42 (1) ◽  
pp. 11-19 ◽  
Author(s):  
MZ Alam ◽  
L Regioneiri ◽  
MAS Santos

The synthesis of protein according to genetic code of a gene determines the basis of life and a stable proteome is necessary for cell homeostatis. However, errors occur naturally during translation of protein from its mRNA, which varies from 10-3 to 10-4 per codon. These errors are more frequent in recombinant protein overexpressed in heterologous hosts and affect protein functionality. The increasing amount of nonfunctional protein is often related to mistranslation of a gene under stress. In the present study, Saccharomyces cerevisiae as a host organism to overexpress E. coli lacZ gene fusion with GST to quantify misincorporation of amino acid in GST-? galactosidase recombinant protein. The yeast was treated with various stressors such as ethanol, chromium (CrO3), and aminoglycoside antibiotic - geneticin (G418) to induce protein aggregation. The misincorporation of amino acids was studied in soluble protein fractions by mass-spectrometry to determine how much misincorporation occur. We found that under experimental stress conditions the misincorporation of amino acids ranges from 5.6 ×10-3 to 8 × 10-3, which represents 60-80 fold higher than reported level. DOI: http://dx.doi.org/10.3329/bjas.v42i1.15760 Bang. J. Anim. Sci. 2013. 42 (1): 11-19


2010 ◽  
Vol 191 (7) ◽  
pp. 1229-1238 ◽  
Author(s):  
Christine Salaun ◽  
Jennifer Greaves ◽  
Luke H. Chamberlain

S-palmitoylation describes the reversible attachment of fatty acids (predominantly palmitate) onto cysteine residues via a labile thioester bond. This posttranslational modification impacts protein functionality by regulating membrane interactions, intracellular sorting, stability, and membrane micropatterning. Several recent findings have provided a tantalizing insight into the regulation and spatiotemporal dynamics of protein palmitoylation. In mammalian cells, the Golgi has emerged as a possible super-reaction center for the palmitoylation of peripheral membrane proteins, whereas palmitoylation reactions on post-Golgi compartments contribute to the regulation of specific substrates. In addition to palmitoylating and depalmitoylating enzymes, intracellular palmitoylation dynamics may also be controlled through interplay with distinct posttranslational modifications, such as phosphorylation and nitrosylation.


2017 ◽  
Vol 1 (3) ◽  
pp. 51-51
Author(s):  
H. C. Lee ◽  
P. Singh ◽  
M. M. Metheny ◽  
G. Strasburg ◽  
B. P. Marks ◽  
...  

2021 ◽  
Author(s):  
Asli Can Karaca

Recent studies have indicated that legume proteins can be potentially used as an alternative to animal-derived protein ingredients for many food and biomaterial applications, however some modifications may be first required to improve their functionality since they show relatively lower solubility and functional properties compared to commonly used animal-based proteins. A variety of physical, chemical or biological processes can be used to achieve these modifications in structural, physicochemical, and functional properties of legume proteins. The aim of this chapter was to review the most recent studies focusing on modification of structural properties and improvement of functionality of legume proteins. Effects of processing conditions on protein functionality were discussed. Special emphasis was given to the structure–function mechanisms behind these changes. Since the performance of modified legume proteins has been shown to depend on a variety of factors; parameters used in the modification process have to be optimized to achieve the desired level of improvement in legume protein functionality. Each modification method has been indicated to have its own advantages and limitations in terms of performance and applicability in different food matrices. Further studies are required to investigate the interactions of modified legume proteins with other food components during food processing and storage. Furthermore, additional research on the effects of modification treatments on flavor profile and nutritional properties of legume proteins is needed as well.


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