Browse more peptide research, methods and limitations.
GHRH demonstrated agonist activity at the GHS-R1a (ghrelin receptor) at physiologically relevant concentrations, revealing previously unknown cross-talk between the GHRH and ghrelin receptor systems — explaining some synergistic GH-releasing effects.
Casanueva, Felipe F; Camiña, Jesus P; Carreira, Marcos C; Pazos, Yolanda; Varga, Jozsef L; Schally, Andrew V · In Vitro
N-methylation of peptide backbone amides improves oral bioavailability, proteolytic stability, membrane permeability, and conformational rigidity — the key chemical modification enabling oral peptide drugs, validated by cyclosporine and being applied to new therapeutic peptides.
Chatterjee, Jayanta; Gilon, Chaim; Hoffman, Amnon; Kessler, Horst · Review
Self-assembling peptide hydrogels incorporating matrix metalloproteinase (MMP)-sensitive substrate sequences degraded in response to cell-secreted MMPs during tissue repair, creating enzyme-responsive smart scaffolds that adapt to the wound healing environment.
Chau, Ying; Luo, Ying; Cheung, Alex C Y; Nagai, Yusuke; Zhang, Shuguang; Kobler, James B; Zeitels, Steven M; Langer, Robert · In Vitro
Goat lactoferricin cloned and expressed in E. coli AD494(DE3)pLysS with retained antibacterial activity against test organisms, expanding the recombinant lactoferricin production to a third species source.
Chen, Gen-Hung; Yin, Li-Jung; Chiang, I-Hua; Jiang, Shann-Tzong · In Vitro
Thymosin alpha-1 concatemer expression in E. coli produced multiple peptide copies per fusion protein, with enzymatic cleavage releasing biologically active thymosin alpha-1 — a high-yield manufacturing strategy for this clinical peptide drug.
Chen, Yuhui; Zhao, Lingxia; Shen, Guoan; Cui, Lijie; Ren, Weiwei; Zhang, Hui; Qian, Hongmei; Tang, Kexuan · In Vitro
Kisspeptins activate GPR54 receptor to control GnRH neuron firing, serving as the essential gatekeeper for puberty onset and adult fertility — GPR54 mutations cause both absent puberty (hypogonadotropic hypogonadism) and infertility, establishing kisspeptin as the master reproductive switch.
Colledge, W H · Review
Peptide library sets designed for HIV vaccine immune response testing, obtained from two independent custom peptide suppliers, contained contaminating peptides capable of generating false-positive results mimicking antigen-specific CD8+ T-cell responses. Detailed investigation revealed that an HIV-1 peptide was contaminated with approximately 1% by weight of a human cytomegalovirus (HCMV) peptide commonly used in cellular immunology research. Because HCMV infection is widespread in the population, this contamination triggered genuine but irrelevant T-cell responses that appeared to be HIV-specific. The false positives were consistent enough to mimic real vaccine-induced responses, which could have led to incorrect conclusions about vaccine efficacy.
Currier, Jeffrey R; Galley, Lynee M; Wenschuh, Holger; Morafo, Vivian; Ratto-Kim, Silvia; Gray, Clive M; Maboko, Leonard; Hoelscher, Michael; Marovich, Mary A; Cox, Josephine H ·
KPV (Lys-Pro-Val) enters intestinal epithelial cells and immune cells — including macrophages, T cells, and B cells — via the PepT1 peptide transporter. Once inside, KPV inhibited NF-kappaB activation and reduced IL-8 secretion in cells exposed to TNF-alpha. When PepT1 was silenced with siRNA, these anti-inflammatory effects were abolished. In live mice, oral KPV reduced inflammation in both DSS-induced and TNBS-induced colitis models, as shown by decreased proinflammatory cytokine expression. Critically, PepT1 knockout mice showed no benefit from KPV, confirming that PepT1 is required for the peptide's anti-inflammatory action. This overturns the prior assumption that KPV works through melanocortin receptors.
Dalmasso, Guillaume; Charrier-Hisamuddin, Laetitia; Nguyen, Hang Thi Thu; Yan, Yutao; Sitaraman, Shanthi; Merlin, Didier · Animal Study
Ghrelin addresses cancer cachexia through triple mechanism: appetite stimulation (reversing anorexia), GH/IGF-1-mediated anabolism (opposing muscle wasting), and anti-inflammatory effects (countering inflammatory cytokine-driven catabolism) — emerging as the most comprehensive cachexia therapy.
DeBoer, Mark Daniel · Review
Anti-inflammatory neuropeptides (VIP, PACAP, alpha-MSH/KPV, CGRP, cortistatin) constitute an endogenous immunoregulatory system: generating regulatory T-cells, suppressing pathogenic Th1/Th17 responses, and promoting inflammation resolution — nature's own anti-inflammatory drug class.
Delgado, Mario; Ganea, Doina · Review
VPAC1 receptor gene polymorphisms were associated with RA susceptibility, with RA patients showing altered VIP receptor expression and signaling — providing genetic evidence linking the neuropeptide anti-inflammatory system to autoimmune disease pathogenesis.
Delgado, Mario; Robledo, Gema; Rueda, Blanca; Varela, Nieves; O'Valle, Francisco; Hernandez-Cortes, Pedro; Caro, Marta; Orozco, Gisela; Gonzalez-Rey, Elena; Martin, Javier · Clinical Trial
Lentiviral VIP gene delivery to arthritic joints reduced inflammation, cartilage destruction, and bone erosion in collagen-induced arthritis mice — demonstrating neuropeptide gene therapy as a viable approach for local treatment of autoimmune joint disease.
Delgado, Mario; Toscano, Miguel G; Benabdellah, Karim; Cobo, Marien; O'Valle, Francisco; Gonzalez-Rey, Elena; Martín, Francisco · Animal Study
Chronic ghrelin/GHRP exposure upregulated L-type and T-type high-voltage calcium channels in GC somatotrophs, enhancing calcium-dependent GH exocytosis capacity — a mechanism for sustained or increasing GH response during chronic secretagogue treatment.
Dominguez, Belisario; Avila, Traudy; Flores-Hernandez, Jorge; Lopez-Lopez, Gustavo; Martinez-Rodriguez, Herminia; Felix, Ricardo; Monjaraz, Eduardo · In Vitro
Researchers identified three specific amino acids — leucine (L), valine (V), and aspartic acid (D) — as essential for the anti-angiogenic activity of tumstatin, a peptide derived from collagen type IV that inhibits blood vessel growth in tumors. A 25-amino acid fragment of tumstatin, when administered systemically, inhibited tumor growth and angiogenesis in mice. The peptide binds specifically to αvβ3 integrin on proliferating endothelial cells and localizes to tumor blood vessels in vivo. When combined with bevacizumab (the anti-VEGF antibody), the tumstatin peptide showed significantly improved anti-tumor efficacy against human renal cell carcinoma xenografts compared to either agent alone.
Eikesdal, Hans Petter; Sugimoto, Hikaru; Birrane, Gabriel; Maeshima, Yohei; Cooke, Vesselina G; Kieran, Mark; Kalluri, Raghu ·
Orlistat inhibition of intestinal lipase acutely increased appetite and attenuated GLP-1/PYY satiety responses, proving that fat absorption (not just fat presence) is required for satiety hormone release — the gut must PROCESS fat to signal fullness.
Ellrichmann, Mark; Kapelle, Mario; Ritter, Peter R; Holst, Jens J; Herzig, Karl-Heinz; Schmidt, Wolfgang E; Schmitz, Frank; Meier, Juris J · RCT
Protein hydrolysates directly stimulated CCK secretion from STC-1 enteroendocrine cells and showed partial CCK1 receptor agonist activity, demonstrating dual mechanisms: dietary peptides both trigger satiety hormone release AND directly activate satiety receptors.
Foltz, Martin; Ansems, Patrick; Schwarz, Jessica; Tasker, Maria C; Lourbakos, Afrodite; Gerhardt, Cindy C · In Vitro
Lactoferricin B induced leukemia cell apoptosis through ceramide accumulation, and modulating ceramide metabolism (glucocerebrosidase inhibition) potentiated the killing — identifying the ceramide death pathway as the molecular mechanism for this anticancer peptide.
Furlong, Suzanne J; Ridgway, Neale D; Hoskin, David W · In Vitro
Peptide amphiphile nanofibers self-assembled into scaffolds supporting dental stem cell (DPSC) adhesion, proliferation, and odontogenic differentiation — validating self-assembling peptide biomaterials for injectable dental tissue regeneration applications.
Galler, Kerstin M; Cavender, Adriana; Yuwono, Virany; Dong, He; Shi, Songtao; Schmalz, Gottfried; Hartgerink, Jeffrey D; D'Souza, Rena N · In Vitro
Thymosin alpha-1-thymopentin fusion peptide expressed in P. pastoris retained both components' immunostimulatory activities, creating a dual-function immune peptide combining T-cell modulation (TA1) with thymocyte maturation (TP-5) in a single recombinant molecule.
Gao, Demin; Zhang, Xulong; Zhang, Jian; Cao, Jichao; Wang, Fengshan · In Vitro
Obese women with BED showed distinct postprandial gut peptide profiles (altered ghrelin, PYY3-36, GLP-1) compared to non-binge obese controls, identifying BED-specific gut hormone dysfunction beyond general obesity-related appetite changes.
Geliebter, Allan; Hashim, Sami A; Gluck, Marci E · Clinical Trial
BNP and NT-proBNP serve dual clinical roles: guiding heart failure drug therapy (titration endpoints) and predicting cardiovascular outcomes (mortality, hospitalization risk) — established as essential biomarkers in evidence-based cardiovascular care.
Godkar, Darshan; Bachu, Kalyan; Dave, Bijal; Niranjan, Selva; Khanna, Ashok · Review
GHRP-2 administration prevented endotoxin-induced liver inflammation in rats: reduced hepatic TNF-α, IL-1β, IL-6, and NF-κB activation — demonstrating direct anti-inflammatory hepatoprotection by GH secretagogues independent of GH release.
Granado, Miriam; Martín, Ana Isabel; López-Menduiña, María; López-Calderón, Asunción; Villanúa, M Angeles · Animal Study
Solid-state NMR revealed acylated, tryptophan-methylated lactoferricin peptides inserted deeper into lipid bilayers with stronger membrane disruption, providing molecular-level explanation for how chemical modifications enhance antimicrobial potency.
Greathouse, Denise; Vostrikov, Vitaly; McClellan, Nicole; Chipollini, Juan; Lay, Jack; Liyanage, Rohana; Ladd, Taylor · In Vitro
Novel macrocyclic melanocortin peptides synthesized by microwave-assisted methods showed potent MC1R/MC4R activity, with the macrocyclic constraint improving receptor selectivity and metabolic stability — advancing circular peptide drugs for melanocortin receptor-mediated therapies.
Grieco, Paolo; Cai, Minying; Liu, Lu; Mayorov, Alexander; Chandler, Kevin; Trivedi, Dev; Lin, Guangxin; Campiglia, Pietro; Novellino, Ettore; Hruby, Victor J · In Vitro
Postnatal environment quality produced lasting changes in brain opioid peptide levels (dynorphin, enkephalin) across development into adulthood in Wistar rats, demonstrating enduring early-life programming of the opioid system that may predispose to later psychopathology.
Gustafsson, Lisa; Oreland, Sadia; Hoffmann, Pernilla; Nylander, Ingrid · Animal Study
VIP differentially modulated human T-cell subsets: suppressed CD4+ effector T-cell proliferation/activation while supporting CD4+CD25+ regulatory T-cell function and survival — directly applicable to restoring the effector/regulatory T-cell balance in rheumatoid arthritis.
Gutiérrez-Cañas, Irene; Juarranz, Yasmina; Santiago, Begoña; Martínez, Carmen; Gomariz, Rosa P; Pablos, José Luis; Leceta, Javier · In Vitro
GH/IGF-1 axis decline correlates with Alzheimer's disease progression, with IGF-1 supporting neuronal survival, beta-amyloid clearance, and synaptic function — GH secretagogues that restore this axis may offer neuroprotective therapeutic benefit for dementia.
Gómez, José Manuel · Review
Polymyxin B-resistant Brucella abortus showed modified defensin susceptibility and altered colonization in mice, demonstrating that antimicrobial peptide resistance affects bacterial fitness, virulence, and tissue tropism in vivo — not just simple survival.
Halling, Shirley M; Jensen, Allen E; Olsen, Steven C · Animal Study
Marrow mesenchymal stem cells in self-assembling peptide hydrogels produced spatially organized mineralized bone matrix resembling natural trabecular bone distribution, demonstrating peptide scaffolds can guide not just cell growth but organized bone tissue formation.
Hamada, Kazunori; Hirose, Motohiro; Yamashita, Toshihiko; Ohgushi, Hajime · In Vitro
Contemporary helix stabilization strategies include hydrocarbon stapling, hydrogen bond surrogates, salt bridges, disulfide crosslinks, and unnatural amino acids — chemical approaches that lock therapeutic peptides into bioactive helical conformations for clinical development.
Henchey, Laura K; Jochim, Andrea L; Arora, Paramjit S · Review
Short linear cationic antimicrobial peptides (≤25 residues) can be systematically screened, optimized through SAR rules (charge, hydrophobicity, amphipathicity), and computationally predicted for activity — a practical framework for antimicrobial peptide drug development.
Hilpert, Kai; Fjell, Christopher D; Cherkasov, Artem · Review
Postprandial GLP-1, PYY3-36, and other gut regulatory peptides dramatically increased following gastric bypass, with enhanced hormonal satiety signaling correlating with reduced appetite and caloric intake — hormonal reprogramming, not restriction, as the primary surgical mechanism.
Holdstock, C; Zethelius, B; Sundbom, M; Karlsson, F A; Edén Engström, B · Clinical Trial
AVPR1a and OXTR genetic polymorphisms are associated with human social behavior variation: autism spectrum features, pair-bonding patterns, empathy levels, and social anxiety — establishing the genetic basis for neuropeptide-mediated social behavior.
Israel, Salomon; Lerer, Elad; Shalev, Idan; Uzefovsky, Florina; Reibold, Mathias; Bachner-Melman, Rachel; Granot, Roni; Bornstein, Gary; Knafo, Ariel; Yirmiya, Nurit; Ebstein, Richard P · Review
Mu-opioid peptide agonists and antagonists showed variable Caco-2 monolayer permeability, with some achieving transcellular transport — assessing oral bioavailability potential and identifying which opioid peptide structures achieve gut barrier crossing.
Iwan, Małgorzata; Jarmołowska, Beata; Bielikowicz, Krzysztof; Kostyra, Elzbieta; Kostyra, Henryk; Kaczmarski, Maciej · In Vitro
H. pylori eradication restored gastric ghrelin expression and increased circulating ghrelin levels, correlating with increased appetite and BMI gain — providing the hormonal mechanism for the weight gain commonly observed after successful H. pylori treatment.
Jang, Eun Jeong; Park, Sang Woon; Park, Ju Sang; Park, Sang Jong; Hahm, Ki-Baik; Paik, So Ya; Sin, Mi Kyung; Lee, Eon Sook; Oh, Sang Woo; Park, Cheol Young; Baik, Hyun Wook · Clinical Trial
Peptide-polymer hydrogels designed from fibrin's coiled-coil region self-assembled into scaffolds mimicking natural wound healing matrix, with tunable mechanical properties suitable for tissue engineering — bio-inspired design from the body's own clotting protein.
Jing, Peng; Rudra, Jai S; Herr, Andrew B; Collier, Joel H · In Vitro
Native chemical ligation crosslinking of self-assembling peptide hydrogels enabled tunable mechanical properties (stiffness, resilience), allowing scaffolds to match tissue-specific mechanical environments — precision biomaterial engineering for diverse tissue regeneration.
Jung, Jangwook P; Jones, Julia L; Cronier, Samantha A; Collier, Joel H · In Vitro
In the DSS-colitis model, KPV treatment led to significantly earlier recovery and stronger body weight regain compared to controls (p<0.01). Inflammatory cell infiltration was significantly reduced (p<0.05). In the adoptive transfer model (a T cell-driven colitis that more closely mimics human IBD), KPV-treated mice had significantly lower clinical scores, less body weight loss, and lower grades of tissue inflammation on histology. In vitro, KPV inhibited TNF-alpha-induced IL-8 secretion in intestinal epithelial cells, demonstrating a direct anti-inflammatory mechanism at the cellular level.
Kannengiesser, K; Maaser, C; Heidemann, J; Luegering, A; Ross, M; Brzoska, T; Böhm, M; Luger, T A; Domschke, W; Kucharzik, T · Animal Study
Different macronutrients trigger distinct gut peptide profiles: protein produces the strongest and most diverse satiety peptide response (GLP-1, PYY, CCK); fat strongly triggers CCK/GLP-1; carbohydrate mainly GIP/insulin; fiber enhances GLP-1/PYY through fermentation — macronutrient-specific appetite pharmacology.
Karhunen, L J; Juvonen, K R; Huotari, A; Purhonen, A K; Herzig, K H · Review
Hormone-based fuel metabolism drugs span GLP-1 agonists (semaglutide class), amylin analogs (pramlintide), PYY analogs, and ghrelin modulators for integrated obesity/diabetes treatment — exploiting endogenous regulatory peptide systems for superior metabolic control.
Kesty, Nicole C; Roth, Jonathan D; Maggs, David · Review
Nicotine antinociception involved spinal met-enkephalin release confirmed by intrathecal anti-met-enkephalin antibody blocking, extending the drug-endogenous opioid amplification mechanism to nicotine — explaining some of smoking's pain-modifying effects.
Kiguchi, Norikazu; Maeda, Takehiko; Tsuruga, Mie; Yamamoto, Akihiro; Yamamoto, Chizuko; Ozaki, Masanobu; Kishioka, Shiroh · Animal Study
BPC-157 (PL14736, in IBD clinical trials) effectively healed various types of healing-impaired wounds in rats including steroid-impaired, denervated, and complex soft tissue injuries — expanding its clinical development potential from IBD to wound healing indications.
Klicek, Robert; Sever, Marko; Radic, Bozo; Drmic, Domagoj; Kocman, Ivan; Zoricic, Ivan; Vuksic, Tihomir; Ivica, Mihovil; Barisic, Ivan; Ilic, Spomenko; Berkopic, Lidija; Vrcic, Hrvoje; Brcic, Luka; Blagaic, Alenka Boban; Coric, Marijana; Brcic, Iva; Rokotov, Dinko Stancic; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag · Animal Study
Ghrelin's complete structural-functional profile: 28 amino acids with essential octanoyl modification on Ser3, GHS-R1a receptor activation, widespread tissue expression, and validated functions in GH release, appetite, energy homeostasis, and cardiovascular protection.
Kojima, Masayasu; Kangawa, Kenji · Review
Chronic psychosocial stress produced CRF alterations in the PVN and central amygdala correlating with increased anxiety-like behavior, mapping how chronic social stress reprograms the brain's CRF stress system to produce persistent anxiety.
Kozicz, T; Bordewin, L A P; Czéh, B; Fuchs, E; Roubos, E W · Animal Study
Plasma MMP-2, TIMP-1, and osteopontin correlated with BNP levels and heart failure severity, providing remodeling biomarkers complementing natriuretic peptides — matrix markers capture the structural damage that peptide markers capture functionally.
Kramer, Frank; Sandner, Peter; Klein, Martina; Krahn, Thomas · Animal Study
New diabetes drugs include GLP-1 agonists (exenatide, liraglutide: injectable, weight loss, low hypo risk), DPP-4 inhibitors (sitagliptin, vildagliptin: oral, weight neutral), and amylin analog (pramlintide) — peptide-based drugs transforming type 2 diabetes treatment.
Krentz, Andrew J; Patel, Mayank B; Bailey, Clifford J · Review
BPC-157 improved early functional recovery (load-to-failure, stiffness) of transected Achilles tendon-to-bone unit, with efficacy maintained during concurrent methylprednisolone — confirming dual tendon-healing and steroid-impairment-overcoming capabilities.
Krivic, A; Majerovic, M; Jelic, I; Seiwerth, S; Sikiric, P · Animal Study
In-vivo microdialysis showed acute ethanol directly triggered beta-endorphin and met-enkephalin release in the central amygdala, providing real-time evidence for alcohol's emotional/anxiolytic effects through local opioid peptide release in the brain's fear center.
Lam, Minh P; Marinelli, Peter W; Bai, Li; Gianoulakis, Christina · Animal Study
Pro-ghrelin and GHS-R1A gene polymorphisms and haplotypes were associated with heavy alcohol use and BMI in humans, providing genetic evidence linking the ghrelin system to both alcohol addiction vulnerability and body weight regulation.
Landgren, Sara; Jerlhag, Elisabet; Zetterberg, Henrik; Gonzalez-Quintela, Arturo; Campos, Joaquin; Olofsson, Ulrica; Nilsson, Staffan; Blennow, Kaj; Engel, Jörgen A · Cross Sectional
A single inhaled dose of aviptadil (100 μg), a synthetic form of vasoactive intestinal peptide (VIP), caused selective pulmonary vasodilation in patients with chronic pulmonary hypertension. The peptide improved stroke volume and mixed venous oxygen saturation — indicating reduced strain on the right ventricle — without affecting systemic blood pressure. Six of 20 patients (30%) achieved a clinically meaningful >20% reduction in pulmonary vascular resistance. In patients with significant lung disease, aviptadil also tended to improve oxygenation. The effect was modest and temporary (as expected from a single dose), but no side effects were reported. The selective pulmonary vasodilation means the drug targeted the lung blood vessels specifically without dropping blood pressure throughout the rest of the body.
Leuchte, H H; Baezner, C; Baumgartner, R A; Bevec, D; Bacher, G; Neurohr, C; Behr, J · Clinical Trial (Uncontrolled)