Current Protein and Peptide Science - Volume 24, Issue 7, 2023

Background: The venom of Crotalus durissus terrificus, as well as its fractions, has intrigued research groups worldwide who are working to isolate, characterize, and find possible biotechnological applications. A number of studies have elucidated that these fractions and their derivatives possess pharmacological properties, which can enable the development of new drug prototypes with anti-inflammatory, antinociceptive, antitumor, antiviral, and antiparasitic applications. Objective: This review presents a systematic study on Crotalus durissus terrificus, the most notable crotalid subspecies in South America, focusing on the composition, toxicological mechanisms, structural aspects, and applications of the main venom toxins (convulxin, gyroxin, crotamine, crotoxin, and their subunits). Conclusion: The authors have found that research on this snake and its toxins is still an area of focus, despite that almost a century has passed since the isolation of crotoxin. Several applications of these proteins in the development of novel drugs and bioactive substances have also been demonstrated.

As more antibiotics become ineffective due to drug-resistant bacteria, alternative therapies for infections must be prioritized. While pathogenic bacteria are a major threat, they also supply a massive reservoir of potential drugs for treating a wide range of illnesses. The concerning emergence of antimicrobial resistance and the rapidly dwindling therapeutic pipeline need the quick discovery and development of new antibiotics. Despite their great promise for natural product medicine development, pathogenic microorganisms have remained mostly unexplored and understudied. We review the antibacterial activity of specialized metabolites derived from pathogenic bacteria, emphasizing those presently in pre-clinical studies or with promise for medication development. Several atypical biosynthetic pathways are outlined, together with the crucial functions. We also discuss the mechanism of action and antibacterial activities of the antibiotics under consideration. Pathogenic bacteria as a rich source of antibiotics, along with recent advances in genomics and natural product research methods, may usher in a new golden age of antibiotic discovery.

Due to the excessive and inappropriate use of antibiotics in farming and clinic, pathogens developed resistance mechanisms to currently used drugs. Thus, because of this resistance, drugs become ineffective, leading to public health problems worldwide. According to the World Health Organization (WHO), microbial resistance to drugs is one of the most threats that humanity must face. Therefore, it is imperative to seek alternative methods to overcome microbial resistance. Here, the potential of natural or synthetic antimicrobial peptides to overcome microbial resistance will be discussed, and how peptides could be a source for new therapeutics molecules. In this context, antimicrobial peptides (natural or synthetic) are considered promising molecules based on their antifungal, antiviral, and antibacterial properties, making them eligible for developing new drugs. In addition, they can act synergistically with existing drugs on the market, revealing a broad spectrum of applications.

Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS), including the brain, spinal cord, and optic nerves. The symptoms can vary from muscle weakness to vision loss. In the case of MS, the immune system attacks the myelin sheath, which protects the nerve fiber and causes inflammation resulting in demyelination. The myelin sheath has the composition of various proteins including membrane proteins and glycoproteins. The four main proteins namely Myelin Basic Protein (MBP), Myelin associated Oligodendrocyte Basic protein (MOBP), Myelin Proteolipid Protein (PLP) and Myelin Associated Glycoprotein (MAG) are known to be critical auto-antigens in causing demyelination in CNS leading to MS. Three out of these four proteins are intrinsically disordered proteins and in this review, we attempted to understand how these proteins play a crucial role in maintaining the integrity of myelin, by exploring its structural and functional aspects and also their auto-antigenicity leading to multiple sclerosis.

Aims: The present work considers the Sulphate import ABC transporter protein (cysA) as a potential drug target for the identification of inhibitors for the protein. Background: The ABC (ATP binding cassette) transporters play a crucial role in the survival and virulence of Mycobacterium tuberculosis by the acquisition of micronutrients from host tissue. Objectives: The 3D structural features of the cysA protein are built. Molecular scaffolds are identified by implementing active site identification, ADME properties, Virtual Screening, and a few other computational techniques. Methods: The theoretical model of cysA is predicted using homology modeling protocols, and the structure is validated by various validation methods. The prediction of partial dimer formation through protein-protein docking methods gave insight into the conformational changes taking place in the cysA protein. The natural substrate ATP is docked with cysA protein that confirms the ATP binding site. To find the drug-like compounds, virtual screening studies were carried out around the active site by several ligand databases. Results: The findings demonstrate the significance of residues SER41, GLY42, ARG50, GLN85, HIS86, LYS91, ARG142, and ASP161 in drug-target interactions. The docking studies of existing TB drugs against cysA were also performed. The result analysis shows that none of the existing drugs inhibits the ATP active site, which confirms cysA as a promising drug target. Using in-silico methods, the ADME parameters of a few chosen ligand molecules are predicted and contrasted with the ADME characteristics of the available TB medications. Conclusion: The results revealed the values of ADME parameters of selected ligand molecules are more permissible than existing TB drugs, which emphasizes the drug-like activity of ligand molecules by inhibition of cysA proteins. The structural data, active site information, and selected ligand molecules help in the identification of new therapeutic scaffolds for Tuberculosis.

Background: Despite the promising clinical potential of bone morphogenetic protein (BMP)-related therapies for bone formation, their side effects warrant the need for alternative therapeutic peptides. BMP family members can aid in bone repair; however, peptides derived from BMP2/ 4 have not yet been investigated. Methods: In this study, three candidates BMP2/4 consensus peptide (BCP) 1, 2, and 3 were identified and their ability to induce osteogenesis in C2C12 cells was analyzed. First, an alkaline phosphatase (ALP) staining assay was performed to evaluate the osteogenic effects of BCPs. Next, the effects of BCPs on RNA expression levels and protein abundances of osteogenic markers were explored. Furthermore, the transcriptional activity of ALP by BCP1 and in silico molecular docking model on BMP type IA receptor (BRIA) were performed. Results: BCP1-3 induced higher RUNX2 expression than BMP2. Interestingly, among them, BCP1 significantly promoted osteoblast differentiation more than BMP2 in ALP staining with no cytotoxicity. BCP1 significantly induced the osteoblast markers, and the highest RUNX2 expression was observed at 100 ng/mL compared to other concentrations. In transfection experiments, BCP1 stimulated osteoblast differentiation via RUNX2 activation and the Smad signaling pathway. Finally, in silico molecular docking suggested the possible binding sites of BCP1 on BRIA. Conclusion: These results show that BCP1 promotes osteogenicity in C2C12 cells. This study suggests that BCP1 is the most promising candidate peptide to replace BMP2 for osteoblast differentiation.