Analysis Update—Full Spectrum Cannabis
Betty Wedman-St Louis in Cannabis as Medicine, 2019
There are 500 naturally occurring amino acids in nature, but only 20 appear in the genetic code. Of those 20 amino acids, 9 are considered essential amino acids, meaning they cannot be produced by the body and must come from the diet. The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Amino acids contain functional groups consisting of an amine (–NH2) and a carboxyl (–COOH) group as well as a side chain (R group). Peptides form when the amine group of one amino acid combines with the carboxyl group of another amino acid. Amino acids are called peptides when a molecule contains a chain of 2–50 amino acids linked together. To be more specific, chains of 20–50 amino acids are referred to as polypeptides; beyond 50 amino acids, the peptides chains are referred to as proteins. Amino acids have been called the building blocks of life. Lacking enough of an essential amino acid will handicap the synthesis of proteins. In the opposite direction, when one consumes proteins, they are broken down in the body to form beneficial amino acids.
Single Amino Acids
Luke R. Bucci in Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Proteins are composed of amino acids linked together into discrete chains. Peptides are short chains of amino acids (2 to 20 amino acid residues). Amino acids are the precursors and raw materials for proteins, peptides, nucleotides, and parts of phospholipids. Amino acid metabolism encompasses and directly impacts almost every aspect of cellular function. Pools of individual amino acids exist inside of cells, in plasma, and in other extracellular fluids. Amino acids are ubiquitous in the human body. This chapter will explore the use of individual amino acids for enhancement of musculoskeletal healing. The range of studies is from enhanced absorption of minerals to pharmacological pain control, illustrating the enormous breadth of functions for amino acids. One caveat must be considered about single amino acids, or, for that matter, any single nutrient. The human metabolism and the healing response is a complex, dynamic system with numerous homeostatic controls. Simply adding one ingredient to a complex system may or may not accentuate the desired result, or it may have unforeseen consequences. In other words, adding a single nutrient to metabolism and expecting it to exert measurable effects on the net outcome is an uphill climb. Nevertheless, with the widespread availability of pure, individual amino acids, a considerable literature has accumulated on the effects of single amino acids on musculoskeletal healing.
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.
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.
Antinociceptive peptides from venomous arthropods
Published in Toxin Reviews, 2023
Jessica A. I. Muller, Lai Y. Chan, Monica C. Toffoli-Kadri, Marcia R. Mortari, David J. Craik, Johannes Koehbach
Well studied peptides include, for example, GpTx-1, GsMTx4, PcTx1, huwentoxins (HwTx), hainantoxins (HNTX), μ-TRTX-Pn3a, protoxins and PnTx. All these peptides have been characterized on validated pain targets in vitro and show analgesic potential in in vivo assays and have recently been reviewed (Akef 2018, Hamad et al.2018, Wu et al.2018, Cardoso and Lewis 2019, Wu et al.2019, Lauria et al.2020, Neff and Wickenden 2021). On the other hand, many peptides are not thoroughly studied, being described only by individual electrophysiological or animal assays (Table 1). Although peptides that block or reduce pain signal transmission at validated pain targets in vitro have the potential to reduce pain in vivo, assays with animal models are needed to verify this activity, and many peptides lack this in vivo information. Likewise, in vivo assays alone are insufficient, as they cannot identify the mechanism or target by which the peptide exhibits its antinociceptive effects. It is therefore imperative to corroborate observed in vivo or in vitro activities. Therefore, we recommend referring to compounds that lack in vivo data as ‘potential analgesic peptides’ (see Sections 2.2, 3.2 and 4.2). Peptides that have been extensively studied will not be discussed in detail here and we focus on peptides that have not been reviewed before.