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International Journal of Molecular... Jul 2023Thyrotropin-releasing hormone (TRH) is a tripeptide that regulates the neuroendocrine thyroid axis. Moreover, its widespread brain distribution has indicated that it is... (Review)
Review
Thyrotropin-releasing hormone (TRH) is a tripeptide that regulates the neuroendocrine thyroid axis. Moreover, its widespread brain distribution has indicated that it is a relevant neuromodulator of behaviors such as feeding, arousal, anxiety, and locomotion. Importantly, it is also a neurotrophic peptide, and thus may halt the development of neurodegenerative diseases and improve mood-related disorders. Its neuroprotective actions on those pathologies and behaviors have been limited due to its poor intestinal and blood-brain barrier permeability, and because it is rapidly degraded by a serum enzyme. As new strategies such as TRH intranasal delivery emerge, a renewed interest in the peptide has arisen. TRH analogs have proven to be safe in animals and humans, while not inducing alterations in thyroid hormones' levels. In this review, we integrate research from different approaches, aiming to demonstrate the therapeutic effects of TRH, and to summarize new efforts to prolong and facilitate the peptide's actions to improve symptoms and the progression of several pathologies.
Topics: Animals; Humans; Thyrotropin-Releasing Hormone; Brain; Thyroid Gland; Peptides; Thyroid Hormones
PubMed: 37446225
DOI: 10.3390/ijms241311047 -
Journal of Peptide Science : An... Apr 2024Newer solid-phase peptide synthesis and release strategies enable the production of short peptides with high purity, allowing direct screening for desired bioactivity...
Newer solid-phase peptide synthesis and release strategies enable the production of short peptides with high purity, allowing direct screening for desired bioactivity without prior chromatographic purification. However, the maximum number of peptides that can currently be synthesized per microplate reactor is 96, allowing the parallel synthesis of 384 peptides in modern devices that have space for 4 microplate reactors. To synthesize larger numbers of peptides, we modified a commercially available peptide synthesizer to enable the production of peptides in 384-well plates, which allows the synthesis of 1,536 peptides in one run (4 × 384 peptides). We report new hardware components and customized software that allowed for the synthesis of 1,536 short peptides in good quantity (average > 0.5 μmol), at high concentration (average > 10 mM), and decent purity without purification (average > 80%). The high-throughput peptide synthesis, which we developed with peptide drug development in mind, may be widely used for peptide library synthesis and screening, antibody epitope scanning, epitope mimetic development, or protease/kinase substrate screening.
Topics: Combinatorial Chemistry Techniques; Solid-Phase Synthesis Techniques; Peptide Library; Peptides; Epitopes
PubMed: 38220145
DOI: 10.1002/psc.3555 -
Marine Drugs Oct 2023It is evident that zinc supplementation is essential for maintaining good health and preventing disease. In this study, a novel oyster peptide-zinc complex with an...
It is evident that zinc supplementation is essential for maintaining good health and preventing disease. In this study, a novel oyster peptide-zinc complex with an average molecular weight of 500 Da was prepared from oyster meat and purified using ultrafiltration, ultrasound, a programmed cooling procedure, chelating, and dialysis. The optimal chelating process parameters obtained through a response surface methodology optimization design are a peptide/zinc ratio of 15, pH of 6.53, reaction time of 80 min, and peptide concentration of 0.06 g/mL. Then, the structure of a peptide-zinc complex (named COP2-Zn) was investigated using the UV and infrared spectrums. The results showed that the maximum absorption peak was redshifted from 224.5 nm to 228.3 nm and the main difference of the absorption peaks was 1396.4 cm. The cytotoxicity and antiproliferative effects of COP2-Zn were evaluated. The results showed that COP2-Zn had a better antiproliferative effect than the unchelated peptide against HepG cells. A DNA flow cytometric analysis showed that COP2-Zn induced S-phase arrest in HepG cells in a dose-dependent manner. Additionally, the flow cytometer indicated that COP2-Zn significantly induced HepG cell apoptosis.
Topics: Animals; Zinc; Chelating Agents; Ostreidae; Peptides
PubMed: 37888477
DOI: 10.3390/md21100542 -
The Journal of Biological Chemistry Oct 2023Family B2 or adhesion G protein-coupled receptors (AGPCRs) are distinguished by variable extracellular regions that contain a modular protease, termed the GPCR...
Family B2 or adhesion G protein-coupled receptors (AGPCRs) are distinguished by variable extracellular regions that contain a modular protease, termed the GPCR autoproteolysis-inducing domain that self-cleaves the receptor into an N-terminal fragment (NTF) and a C-terminal fragment (CTF), or seven transmembrane domain (7TM). The NTF and CTF remain bound after cleavage through noncovalent interactions. NTF binding to a ligand(s) presented by nearby cells, or the extracellular matrix anchors the NTF, such that cell movement generates force to induce NTF/CTF dissociation and expose the AGPCR tethered peptide agonist. The released tethered agonist (TA) binds rapidly to the 7TM orthosteric site to activate signaling. The orphan AGPCR, GPR114 was reported to be uncleaved, yet paradoxically capable of activation by its TA. GPR114 has an identical cleavage site and TA to efficiently cleave GPR56. Here, we used immunoblotting and biochemical assays to demonstrate that GPR114 is a cleaved receptor, and the self-cleavage is required for GPR114 TA-activation of Gs and no other classes of G proteins. Mutagenesis studies defined features of the GPR114 and GPR56 GAIN subdomains that influenced self-cleavage efficiency. Thrombin treatment of protease-activated receptor 1 leader/AGPCR fusion proteins demonstrated that acute decryption of the GPR114/56 TAs activated signaling. GPR114 was found to be expressed in an eosinophilic-like cancer cell line (EoL-1 cells) and endogenous GPR114 was efficiently self-cleaved. Application of GPR114 TA peptidomimetics to EoL-1 cells stimulated cAMP production. Our findings may aid future delineation of GPR114 function in eosinophil cAMP signaling related to migration, chemotaxis, or degranulation.
Topics: Cell Adhesion; Peptides; Protein Binding; Protein Domains; Receptors, G-Protein-Coupled; Signal Transduction; Humans
PubMed: 37673336
DOI: 10.1016/j.jbc.2023.105223 -
Biotechnology Journal Jan 2024Peptide drugs are developed from endogenous or synthetic peptides with specific biological activities. They have advantages of strong target specificity, high efficacy... (Review)
Review
Peptide drugs are developed from endogenous or synthetic peptides with specific biological activities. They have advantages of strong target specificity, high efficacy and low toxicity, thus showing great promise in the treatment of many diseases such as cancer, infections, and diabetes. Although an increasing number of peptide drugs have entered market in recent years, the preparation of peptide drug substances is yet a bottleneck problem for their industrial production. Comparing to the chemical synthesis method, peptide biosynthesis has advantages of simple synthesis, low cost, and low contamination. Therefore, the biosynthesis technology of peptide drugs has been widely used for manufacturing. Herein, we reviewed the development of peptide drugs and recent advances in peptide biosynthesis technology, in order to shed a light to the prospect of industrial production of peptide drugs based on biosynthesis technology.
Topics: Humans; Industrial Development; Peptides; Neoplasms; Technology; Industry
PubMed: 37884278
DOI: 10.1002/biot.202300256 -
International Journal of Molecular... Sep 2023Coiled-coil domains (CCDs) play key roles in regulating both healthy cellular processes and the pathogenesis of various diseases by controlling protein self-association...
Coiled-coil domains (CCDs) play key roles in regulating both healthy cellular processes and the pathogenesis of various diseases by controlling protein self-association and protein-protein interactions. Here, we probe the mechanism of oligomerization of a peptide representing the CCD of the STIL protein, a tetrameric multi-domain protein that is over-expressed in several cancers and associated with metastatic spread. STIL tetramerization is mediated both by an intrinsically disordered domain (STIL) and a structured CCD (STIL CCD). Disrupting STIL oligomerization via the CCD inhibits its activity We describe a comprehensive biophysical and structural characterization of the concentration-dependent oligomerization of STIL CCD peptide. We combine analytical ultracentrifugation, fluorescence and circular dichroism spectroscopy to probe the STIL CCD peptide assembly in solution and determine dissociation constants of both the dimerization, (K = 8 ± 2 µM) and tetramerization (K = 68 ± 2 µM) of the WT STIL CCD peptide. The higher-order oligomers result in increased thermal stability and cooperativity of association. We suggest that this complex oligomerization mechanism regulates the activated levels of STIL in the cell and during centriole duplication. In addition, we present X-ray crystal structures for the CCD containing destabilising (L736E) and stabilising (Q729L) mutations, which reveal dimeric and tetrameric antiparallel coiled-coil structures, respectively. Overall, this study offers a basis for understanding the structural molecular biology of the STIL protein, and how it might be targeted to discover anti-cancer reagents.
Topics: Biophysical Phenomena; Circular Dichroism; Dimerization; Peptides; Protein Domains; Proteins; Humans; Intracellular Signaling Peptides and Proteins
PubMed: 37834064
DOI: 10.3390/ijms241914616 -
European Biophysics Journal : EBJ Oct 2023Peptide nucleic acid (PNA) is a nucleic acid mimic with high specificity and binding affinity to natural DNA or RNA, as well as resistance to enzymatic degradation. PNA... (Review)
Review
Peptide nucleic acid (PNA) is a nucleic acid mimic with high specificity and binding affinity to natural DNA or RNA, as well as resistance to enzymatic degradation. PNA sequences can be designed to selectively silence gene expression, which makes PNA a promising tool for antimicrobial applications. However, the poor membrane permeability of PNA remains the main limiting factor for its applications in cells. To overcome this obstacle, PNA conjugates with different molecules have been developed. This mini-review focuses on covalently linked conjugates of PNA with cell-penetrating peptides, aminosugars, aminoglycoside antibiotics, and non-peptidic molecules that were tested, primarily as PNA carriers, in antibacterial and antiviral applications. The chemistries of the conjugation and the applied linkers are also discussed.
Topics: Peptide Nucleic Acids; Anti-Bacterial Agents; Amino Acid Sequence; Cell-Penetrating Peptides
PubMed: 37610696
DOI: 10.1007/s00249-023-01673-w -
Accounts of Chemical Research Jul 2023Chemical manipulation of naturally occurring peptides offers a convenient route for generating analogs to screen against different therapeutic targets. However, the...
Chemical manipulation of naturally occurring peptides offers a convenient route for generating analogs to screen against different therapeutic targets. However, the limited success of the conventional chemical libraries has urged chemical biologists to adopt alternative methods such as phage and mRNA displays and create libraries of a large number of variants for the screening and selection of novel peptides. Messenger RNA (mRNA) display provides great advantages in terms of the library size and the straightforward recovery of the selected polypeptide sequences. Importantly, the integration of the flexible translation (FIT) system with the mRNA display provides the basis of the random nonstandard peptides integrated discovery (RaPID) approach for the introduction of diverse nonstandard motifs, such as unnatural side chains and backbone modifications. This platform allows the discovery of functionalized peptides with tight binding against virtually any protein of interest (POI) and therefore shows great potential in the pharmaceutical industry. However, this method has been limited to targets generated by recombinant expression, excluding its applications to uniquely modified proteins, particularly those with post-translational modifications.Chemical protein synthesis allows a wide range of changes to the protein's chemical composition to be performed, including side chain and backbone modifications and access to post-translationally modified proteins, which are often inaccessible or difficult to achieve via recombinant expression methods. Notably, d-proteins can be prepared via chemical synthesis, which has been used in mirror image phase display for the discovery of nonproteolytic d-peptide binders.Combining chemical protein synthesis with the RaPID system allows the production of a library of trillions of cyclic peptides and subsequent selection for novel cyclic peptide binders targeting a uniquely modified protein to assist in studying its unexplored biology and possibly the discovery of new drug candidates.Interestingly, the small post-translational modifier protein ubiquitin (Ub), with its various polymeric forms, regulates directly or indirectly many biochemical processes, e.g., proteasomal degradation, DNA damage repair, cell cycle regulation, etc. In this Account, we discuss combining the RaPID approach against various synthetic Ub chains for selecting effective and specific macrocyclic peptide binders. This offers an advancement in modulating central Ub pathways and provides opportunities in drug discovery areas associated with Ub signaling. We highlight experimental approaches and conceptual adaptations required to design and modulate the activity of Lys48- and Lys63-linked Ub chains by macrocyclic peptides. We also present the applications of these approaches to shed light on related biological activities and ultimately their activity against cancer. Finally, we contemplate future developments still pending in this exciting multidisciplinary field.
Topics: Peptides; Proteins; Peptides, Cyclic; Drug Discovery; RNA, Messenger; Peptide Library
PubMed: 37312234
DOI: 10.1021/acs.accounts.3c00178 -
ACS Nano Sep 2023Better insights into the fate of membraneless organelles could strengthen the understanding of the transition from prebiotic components to multicellular organisms....
Better insights into the fate of membraneless organelles could strengthen the understanding of the transition from prebiotic components to multicellular organisms. Compartmentalized enzyme reactions in a synthetic coacervate have been investigated, yet there remains a gap in understanding the enzyme interactions with coacervate as a substrate hub. Here, we study how the molecularly crowded nature of the coacervate affects the interactions of the embedded substrate with a protease. We design oligopeptide-based coacervates that comprise an anionic Asp-peptide (D) and a cationic Arg-peptide (RR) with a proteolytic cleavage site. The coacervates dissolve in the presence of the main protease (M) implicated in the coronavirus lifecycle. We capitalize on the condensed structure, introduce a self-quenching mechanism, and model the enzyme kinetics by using Cy5.5-labeled peptides. The determined specificity constant (/K) is 5817 M s and is similar to that of the free substrate. We further show that the enzyme kinetics depend on the type and quantity of dye incorporated into the coacervates. Our work presents a simple design for enzyme-responsive coacervates and provides insights into the interactions between the enzyme and coacervates as a whole.
Topics: Proteins; Peptides; Oligopeptides; Peptide Hydrolases
PubMed: 37579082
DOI: 10.1021/acsnano.3c04259 -
General and Comparative Endocrinology Nov 2023In starfish, a relaxin-like gonad-stimulating peptide (RGP) acts as a gonadotropin that triggers gamete maturation and spawning. In common with other relaxin/insulin...
In starfish, a relaxin-like gonad-stimulating peptide (RGP) acts as a gonadotropin that triggers gamete maturation and spawning. In common with other relaxin/insulin superfamily peptides, RGP consists of an A- and a B-chain, with cross-linkages mediated by one intra- and two inter-chain disulfide bonds. In this study, a second relaxin-like peptide (RLP2) was identified in starfish species belonging to the orders Valvatida, Paxillosida, and Forcipulatida. Like RGP, RLP2 precursors comprise a signal peptide and a C-peptide in addition to the A- and B-chains. However, a unique cysteine motif [CC-(3X)-C-(10X)-C] is present in the A-chain of RLP2, which contrasts with the cysteine motif in other members of the relaxin/insulin superfamily [CC-(3X)-C-(8X)-C]. Importantly, in vitro pharmacological tests revealed that Patiria pectinifera RLP2 (Ppe-RLP2) and Asterias rubens RLP2 (Aru-RLP2) trigger shedding of mature eggs from ovaries of P. pectinifera and A. rubens, respectively. Furthermore, the potencies of Ppe-RLP2 and Aru-RLP2 as gonadotropic peptides were similar to those of Ppe-RGP and Aru-RGP, respectively, and the effect of RLP2 exhibited partial species-specificity. These findings indicate that two relaxin-type peptides regulate spawning in starfish and therefore we propose that RGP and RLP2 are renamed RGP1 and RGP2, respectively.
Topics: Animals; Starfish; Relaxin; Cysteine; C-Peptide; Asterias; Asterina; Insulin
PubMed: 37611673
DOI: 10.1016/j.ygcen.2023.114369