Modern peptides are generally classified to medical peptide drugs ( peptide antibiotics, vaccines, agricultural antimicrobial peptides, daily cosmetics, etc. ) and food peptides ( soybean peptides, corn polypeptides, yeast polypeptides, sea cucumber peptides, etc. ). From the functional point, current marketing peptides can be divided into antihypertensive peptides, antioxidant peptides, cholesterol peptides, opioid peptides, oligopeptides, and so on.
Commonly, peptides are connected with nutrition, hormones, enzymes inhibition, immune regulation, and anti-oxidation. With the rapid advances in high-level biotechnology, development of peptide drugs has widen to disease prevention and effective treatment, particularly in the following areas.
Antineoplastic Polypeptides
Tumor is caused by a wide range of factors, but ultimately it involves the regulation and expression of oncogenes. Since 2013, scientists have found many tumor-associated genes and regulatory factors that can have an effect on the tumor, screening those peptides connected with the genes and regulatory factors could be necessary, which has now become a new hot spot to find anti-cancer drugs. For example, somatostatin is used to treat digestive endocrine tumors while hexapeptide is helpful for the inhibition of adenocarcinoma in vivo. In addition, Swiss scientists have discovered the octapeptide that can be utilized to induce tumor cells’ apoptosis.
Anti-viral Polypeptides
Virus can absorb the cells by binding to specific receptors on the host cells and then complete the protein processing and nucleic acid replication relying on its own specific protease. Therefore, it’s necessary to screen polypeptides binding to those host cells from a peptide library, or capable of binding to the active site of viral protease polypeptides for anti-viral therapy. Actually, since 2013, scientists from Canada, Italy and other countries have screened mass anti-viral small peptides from a peptide library, some of which can be used in clinical trials.
Cytokine Mimic Peptides
Using a known cytokine receptor to successfully screen the cytokine mimetic peptides from a peptide library has already become the hot research since 2011. Current screening mainly involves body erythropoietin, body thrombopoietin, human growth hormone, nerve growth factor and interleukin-1, etc. The amino acid sequences and corresponding cytokines’ amino acid sequences of these mimetic peptides are actually different, while at the same time with cytokine activity and small relative molecular mass.
Antimicrobial Peptides
The insects will produce large amounts of cationic peptides under external environmental stimuli, but with the antimicrobial activity. In fact, hundreds of antimicrobial peptides have been screened until now. Vivo experiments confirmed that many antimicrobial peptides not only have strong antibacterial function and bactericidal capacity but also own the ability to kill tumor cells.
Peptide Vaccines
Peptide and DNA vaccines have been seen as one of the more valued vaccine studies and many researches and developments are focused on a large number of virus peptide vaccines. Some scientists are trying to develop a multivalent antigen peptide vaccine for malaria; cervical HPV polypeptide vaccine has entered phase II clinical trials.
Additionally, diagnostic polypeptides are also useful for the detection of corresponding pathogen, as an antigen. Clearly, scientific research is endless, meaning more effective medical studies will occur to help with the disease treatment.