Synthesis of Bioactive Peptides for Pharmaceutical Applications
Peter Grunwald in Pharmaceutical Biocatalysis, 2019
The short chains of amino acid monomers are grouped together with peptide bond linkages to form a beneficial biological entity called peptide. These peptides are classified into dipeptide, which is the shortest peptide, tripeptide, and polypeptide based on the number of amino acids required for peptide formation. Peptides contain less than 50 amino acids and are different from proteins which contain functional polypeptides bound with ligands or genetic material. Also, peptides are highly beneficial in molecular biology as they allow the formation of antibiotic peptides without the requirement of purified protein (Muheem et al., 2016). Recently, peptides are used in mass spectroscopy for the identification of protein structure and function, by analyzing sequences and masses of peptide (Aebersold and Mann, 2016). Moreover, inhibitory peptides are utilized to inhibit the proteins related to diseases and are broadly utilized as a curative agent of deadly diseases (Risitano et al., 2014). The synthesis procedure of peptides determines their properties and thus, they are classified based on the method of synthesis used for peptide formation. Bioactivity is an important property of peptides and thus bioactive peptides are widely used in biomedical pharmaceutical applications. Ribosomal, non-ribosomal, peptones, milk-based and peptide fragments are the sub-classes of bioactive peptides that possess enormous applicational importance (Korhonen et al., 2006).
Effects of Neuropeptides on Intestinal Ion Transport
Edwin E. Daniel in Neuropeptide Function in the Gastrointestinal Tract, 2019
Increases in the levels of secretory peptides would be expected to produce diarrhea. In watery diarrhrea syndrome associated with non-B-islet cell tumors, VIP is a prime candidate.2,7,58 Other peptides that could be included are calcitonin, GIP, secretin glucagon, and enteroglucagon.58 Although diarrhea would not be anticipated with somatostatinomas since this peptide promotes absorption, diarrhea has been reported.59,64–69 It is possible in this case that other peptides, such as calcitonin, could be responsible. The involvement of different peptides in tumors of endocrine cells has been well documented and reviewed. The reported incidence of gastroenteropancreatic (GEP) tumors is around 1.5 cases for 100,000 of the general population.59 Carcinoids account for 55%, insulinomas 17%, tumors of unknown types 15%, gastrimonas 9%, and VIPomas 2%.70 It is believed that these tumors arise from a primitive stem cell.
Melanotropin Receptors and Signal Transduction
Mac E. Hadley in The Melanotropic Peptides, 2018
Peptide hormones are physiologically active molecules important in a variety of endocrine, neuroregulatory, and other cellular processes. Structurally, linear and cyclic peptides are composed of an ordered, covalent sequence of amino acids which ultimately defines specific topological and, in a few well-studied examples, conformational features essential to their molecular action.16 Functionally, the biological activity of many peptide hormones on their target cells has been shown to involve interaction with a plasma-membrane-localized, complex regulatory enzyme system including: (1) high-affinity, hormone-specific receptors; (2) guanyl nucleotide-binding proteins; (3) monovalent and divalent metal-binding proteins; and (4) adenylate cyclase. In addition, the phospholipid milieu of the plasma membrane may also provide a regulatory role in biological signal transduction by coordinating the activities of the functional components of this enzyme system. The molecular basis of such peptide-receptor binding and subsequent signal transduction processes are elaborated further in Table
Emerging peptide therapeutics for the treatment of ovarian cancer
Published in Expert Opinion on Emerging Drugs, 2023
Ana C. Veneziani, Eduardo Gonzalez-Ochoa, Amit M. Oza
Peptides are composed of short sequences of amino acids and are held together by peptide bonds. They are structural segments of proteins and are subdivided into oligopeptides and polypeptides [42]. Therapeutic peptides and proteins bind to cell receptors with high affinity and trigger intracellular effects. They are vital for cellular activity, such as cell growth, energy metabolism, material transport, signal transmission, and immune regulation [43–45]. Most of these peptides and proteins are expressed on the tumor cell surface and are classified as tumor-associated antigens (TAA). Other emerging targets are the cancer-testis antigens (CTA), which are expressed in a wide range of cancer types. In contrast, their expression in normal tissues is restricted to immune privileged sites such as testis and placenta [46]. Some of these peptides and proteins are ideal targets for cancer-specific immunotherapy.
Patent landscape highlighting therapeutic implications of peptides targeting myristoylated alanine-rich protein kinase-C substrate (MARCKS)
Published in Expert Opinion on Therapeutic Patents, 2023
Vikas Yadav, Amarish Kumar Sharma, Gaurav Parashar, Nidarshana Chaturvedi Parashar, Seema Ramniwas, Manoj Kumar Jena, Hardeep Singh Tuli, Kiran Yadav
Peptides are short chains of amino acids that are naturally occurring in the body and are known to be involved in various physiological processes. The major advantage of using peptides as drugs is their specificity, as peptides can target specific receptors or enzymes in the body and have a lower potential for off-target effects compared to small-molecule drugs [15,16]. Peptides also offer a lower toxicity profile due to their rapid metabolism and clearance from the body, which helps reduce the risk of long-term adverse effects [17]. However, this characteristic property is sometimes considered as a limitation for peptide-based drug discovery. Several advancements have been postulated to overcome the rapid clearance or proteolytic degradation of peptide-based drugs, but these are beyond the scope of the present review.
Self-assembling peptides-based nano-cargos for targeted chemotherapy and immunotherapy of tumors: recent developments, challenges, and future perspectives
Published in Drug Delivery, 2022
Xue-Jun Wang, Jian Cheng, Le-Yi Zhang, Jun-Gang Zhang
Peptides are amino acid chains made up of about 50 amino acids that are simple to produce and are even designed to mimic the self-assembly (SA) characteristics of proteins. Peptides have outstanding chemical diversity, high biocompatibility, and biological recognition capabilities. Furthermore, small peptides can translocate cell membranes but do not elicit an immunological response (Wang et al., 2019). Though, free peptides are usually unstable and undergo rapid degradation during the body's blood circulation, resulting in an off-target effect (Yang et al., 2018). Consequently, the elegant nanotechnology of the SA approach for modifying peptides and building stable and multifunctional nanomaterials has been developed in recent years specifically for tumor therapy (Yuan et al., 2019). SA is a necessary bottom-up method of construction in the toolkit of current nanotechnology. Today, SA is a growing field of research that incorporates concepts from supramolecular chemistry as well as contributions from chemistry, biology physics, and engineering. Notably, self-assembled materials have a wide range of applications in drug delivery, tissue engineering, electronics, and nanotechnology (Whitesides et al., 1991; Lehn, 2002).