Ensuring resistance to proteolysis of recombinant protein

The aim of the study is to ensure the stability of the recombinant GDF-11 protein by developing a cyc-lized peptide sequence resistant to proteolysis, with subsequent synthesis of a plasmid encoding this se-quence for expression in E. coli. The object of the study is the recombinant CDF-11 protein of the TGF-β protein superfamily. To ensure resistance to proteolysis and bioavailability of the GDF-11 protein, cycliza-tion of the NLCLDCDEHS sequence of the protein was carried out by attaching two cysteine residues to obtain the NCLCLDCDEHCS sequence. The peptide sequence NCLCLDCDEHCS has the following physi-cochemical characteristics: two leucine residues and four cysteines (hydrophobic amino acids), one glu-tamic acid residue and two aspartic acid residues (negatively charged), and one histidine (positively charged). Hydrophobicity is 50 %, the total negative charge is 2.75, Wimley-White hydrophobicity is 3.12 units. The molecular weight of the peptide is 1354.532 Da, the protein binding potential (Boman in-dex) is 1.99 kcal/mol. As a result of predicting the properties of the peptide sequence, it was found that it has optimal lipophilicity and hydrophobicity, is characterized by good solubility, absorption, penetration through cell membranes, is in an unbound state in plasma, has low plasma clearance, a long half-life, which indicates its effectiveness and high clinical efficacy when administered orally and, therefore, is re-sistant to proteolysis. A plasmid was created that encodes the NCLCLDCDEHCS sequence in the GDF-11 protein. For the subsequent production of proteolysis-resistant GDF-11 protein, it will be necessary to in-sert the created plasmid into E. Coli, the metabolite of which will be the above-mentioned protein, which will be the subject of further research.