Gene Optimization | Protein expression | Molecular Biology | Protein | Gene | Basic Science Series

Gene Optimization | Protein expression | Molecular Biology | Protein | Gene | Basic Science Series This presentation will help you to understand the basic concepts of protein expression; it will also help you to improve the purification strategy for better expression of your desired protein in E.coli expression system. please subscribe to the channel for new episodes.

• There are several steps involved in protein manufacturing at the laboratory scale in E.coli. The first step is gene optimization. Here we will focus only on the optimization of gene sequence for E.coli.

• Let's discuss what is gene optimization and why we need it. Living cells use a set of rules called the “genetic code” to translate genetic information encoded in DNA and mRNA into proteins. The code consists of nucleotide triplets, called codons, that specify which amino acid should be added to the growing chain of a peptide during protein synthesis. • • There are 64 different codons. 61 of them encode the 20 standard amino acids, while another 3 functions as stop codons. The greater number of codons relative to the number of amino acids they code for means that a single amino acid can be encoded by more than one codon. Indeed, some common amino acids, such as arginine and leucine, are encoded by as many as 6 codons. • • Different organisms exhibit a bias towards use of certain codons over others for the same amino acid. Some species are known to avoid certain codons almost entirely. Therefore, it is important to consider codon optimization when performing expression studies.

• While numerous factors contribute to the success of protein expression, codon optimization plays a critical role, particularly when proteins are expressed in a heterologous system. As an example, if a human gene is to be expressed in E. coli, choosing codons preferentially used by the bacterium can increase the success of protein expression.

• This is particularly true when rare codons are eliminated. The frequencies with which the different codons appear in genes in E. coli are different from those in genes derived from other organisms. Therefore, various genes that contain codons, which are rare in E. coli, may be inefficiently expressed by this organism. Rare codons can cause premature termination of the synthesized protein or disincorporation of amino acids. ... https://www.youtube.com/watch?v=10EtO9-XCxU