The short version of 二肽基肽酶-4 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
The distinction between established facts and open questions matters here. That the peptide binds the GLP-1 receptor and stimulates insulin release in a glucose-dependent manner is well documented. How individual variability in receptor density, gastric emptying rate, and gut microbiome composition shapes response remains an active research area. Long-term outcomes beyond five years of continuous use are not yet fully characterized in published trials, and several extension studies are ongoing.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1, a hormone released from intestinal L cells after food intake. The molecule is a 31-amino-acid backbone modified at three positions to resist cleavage by dipeptidyl peptidase-4, the enzyme that degrades native GLP-1 within minutes. A lysine residue at position 26 carries a linker and a C18 fatty diacid, which promotes binding to serum albumin and slows renal clearance. These changes extend the circulating half-life from roughly two minutes to about one week in humans.
Clinical development of this compound followed earlier short-acting GLP-1 analogues that required frequent injection. Once-weekly subcutaneous formulations entered use after 2017, and an oral formulation using a permeation enhancer later became available. The oral version pairs the peptide with sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, a carrier that improves uptake across the gastric epithelium. Interest has expanded from glycaemic control into weight management and metabolic liver disease. Regulatory status and approved indications differ between countries, and the product remains subject to ongoing safety monitoring.
Semaglutide is a synthetic peptide that acts as an agonist at the glucagon-like peptide-1 receptor. It is a structural analogue of human GLP-1(7-37), modified to resist enzymatic degradation by dipeptidyl peptidase-4. The peptide backbone contains alpha-aminoisobutyric acid at position 8, a substitution that stabilises the helix and slows cleavage. A fatty diacid side chain attached through a linker at lysine 34 promotes binding to serum albumin, which extends the circulating half-life. These two modifications together allow less frequent administration than native GLP-1 requires.
| Property | Value | Notes |
|---|---|---|
| Molecular formula (free base) | C187H291N45O59 | Approximate; salt and hydrate forms differ |
| Molecular weight | ~4113.6 Da | Varies with counterion and hydration |
| Appearance | White to off-white powder | Lyophilized research material |
| Solubility class | Freely soluble in water | As formulated; native peptide less stable near neutral pH |
| Typical storage | 2 to 8 degrees Celsius | Protect from light; avoid repeated freeze-thaw |
Large randomised trials in adults with type 2 diabetes and in adults with obesity have reported reductions in body weight and improvements in several cardiovascular risk markers. One outcome trial found a lower incidence of major adverse cardiovascular events in participants with diabetes and established cardiovascular disease. Gastrointestinal effects such as nausea and vomiting are the most frequently reported adverse events and often diminish over time. Changes in lean body mass during weight loss are an area of ongoing investigation. Effects in adolescents and in pregnancy are less well characterised, and current labelling advises against use during pregnancy.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released after nutrient intake. The molecule contains 31 amino acid residues and differs from the native sequence at several positions. A non-natural residue at position eight resists the enzyme that normally truncates the hormone, while a lysine-linked fatty diacid side chain promotes binding to serum albumin. These two modifications extend the circulating half-life from minutes to roughly one week. The peptide is produced by solid-phase synthesis followed by selective acylation, and its identity and purity are confirmed by spectrometric and chromatographic techniques.
The primary target is the GLP-1 receptor, a class B G protein-coupled receptor expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises intracellular cyclic AMP, which potentiates glucose-dependent insulin secretion and lowers glucagon release when blood glucose is elevated. Signalling in the hypothalamus and brainstem is associated with reduced appetite and slower gastric emptying. Because the insulinotropic effect depends on prevailing glucose levels, the hypoglycaemic risk of the peptide alone is described as low in most study settings. The relative contribution of peripheral and central actions remains an active research question.
皮下注射后吸收相对缓慢，绝对生物利用度约为百分之八十九，血药浓度峰值通常出现在给药后一到三天。与白蛋白结合使清除减慢，终末半衰期约为一百六十五小时，接近一周。连续给药约四到五周后达到稳态暴露水平。表观分布容积约为每千克零点二五升，血浆蛋白结合率超过百分之九十九。代谢以蛋白水解切割和脂肪二酸侧链的 β-氧化为主，相关产物主要经尿液与粪便排出。
序列层面的改动同时解决了两个问题，即酶解稳定性与肾脏清除速度。天然 GLP-1 在循环中的半衰期仅约两分钟，主要被二肽基肽酶-4 迅速灭活。酰化侧链与白蛋白的可逆结合形成循环储库，使分子缓慢释放并持续激活受体。这种设计思路后来被广泛用于同类长效肽的开发，属于该类药物化学改造的典型范式。
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
Pharmacological activity arises from agonism at the glucagon-like peptide-1 receptor, a G protein-coupled receptor expressed in the pancreas, the gastrointestinal tract, and the brainstem. Receptor activation raises intracellular cyclic adenosine monophosphate and enhances insulin release in a glucose-dependent manner, an effect that diminishes when blood glucose concentration is low. Other effects include slowed gastric emptying and hypothalamic satiety signalling. These pathways are described well. Receptor desensitisation rates across tissues, relative to the endogenous hormone, are still under investigation, and reported findings differ between laboratories.
The company that developed the compound filed it as a long-acting analogue, and it gained first approval in 2017 for type 2 diabetes. Later authorisations from several regulators extended the indication to chronic weight management, and the World Health Organization added the glucagon-like peptide-1 receptor agonist drug class to its model list of essential medicines in 2023. Production uses solid-phase peptide synthesis followed by side-chain conjugation and chromatographic purification. Supply constraints and cost differences across regions are well documented. Literature on long-term outcomes continues to grow, with many trials reporting surrogate endpoints rather than hard clinical endpoints.
Semaglutide is a synthetic peptide of thirty-one amino acids that shares roughly ninety-four percent sequence identity with human glucagon-like peptide-1. Two substitutions resist enzymatic cleavage by dipeptidyl peptidase-4, and a fatty diacid side chain attached through a linker promotes binding to serum albumin. That albumin binding slows renal clearance and extends the circulating half-life from minutes to approximately one week. The structural changes are well established in the published literature. Whether the same modifications affect receptor signalling bias in ways that matter clinically remains an open question.
Lyophilized semaglutide is typically stored at temperatures between minus 20 and minus 80 degrees Celsius for long-term preservation. Short-term storage at 2 to 8 degrees Celsius is common for working aliquots. Repeated freeze-thaw cycles can degrade the peptide and are usually avoided. The molecule is hygroscopic in its solid form, so containers should remain sealed with desiccant. Solutions are less stable than powders and are generally prepared fresh. Light exposure is limited because aromatic residues can undergo photo-oxidation.
Semaglutide dissolves readily in water and in aqueous buffers near neutral pH. Solubility decreases near the isoelectric point, where net charge is minimal. Common laboratory solvents include phosphate-buffered saline and dilute ammonium bicarbonate. Strongly acidic or basic conditions may accelerate hydrolysis. Working concentrations are usually prepared by diluting a concentrated stock. Vial surfaces can adsorb small amounts of peptide at low concentrations, so carrier proteins or low-binding tubes are sometimes used.
In 1902 William Bayliss and Ernest Starling performed an experiment in which they observed that acid instilled into the duodenum caused the pancreas to begin secretion, even after they had removed all nervous connections between the two. The same response could be produced by injecting extract of jejunum mucosa into the jugular vein, showing that some factor in the mucosa was responsible. They named this substance "secretin" and coined the term hormone for chemicals that act in this way. Joseph von Mering and Oskar Minkowski made the observation in 1889 that removing the pancreas surgically led to an increase in blood sugar, followed by a coma and eventual death—symptoms of diabetes mellitus. In 1922, Banting and Best realized that homogenizing the pancreas and injecting the derived extract reversed this condition. Neurohormones were first identified by Otto Loewi in 1921. He incubated a frog's heart (innervated with its vagus nerve attached) in a saline bath, and left in the solution for some time. The solution was then used to bathe a non-innervated second heart. If the vagus nerve on the first heart was stimulated, negative inotropic (beat amplitude) and chronotropic (beat rate) activity were seen in both hearts. This did not occur in either heart if the vagus nerve was not stimulated. The vagus nerve was adding something to the saline solution. The effect could be blocked using atropine, a known inhibitor to heart vagal nerve stimulation. Clearly, something was being secreted by the vagus nerve and affecting the heart.
The Federation of Malaya Executive Council comprised 7 official and 7 unofficial members. The Federation of Malaya Legislative Council comprised the high commissioner as the council president, 14 official and 50 unofficial members representing the Straits Settlements, business groups and all races. Additionally, 9 State Council Yang Di Pertua (heads of state), chief ministers and 2 representatives from the Straits Settlements became unofficial members. The Malay Conference of Rulers would advise the high commissioner on immigration issues. The British Resident was replaced with a chief minister in each state of the federation.
=== NEMS === Nanoelectromechanical systems (NEMS) can be designed and characterized by understanding the interaction and coupling between the mechanical, electrical, and the van der Waals energy domains. Quantum mechanical limit governed by Heisenberg uncertainty relation decides the ultimate precision of nanomechanical systems. Quantum squeezing can improve the precision by reducing quantum fluctuations in one desired amplitude of the two quadrature amplitudes. Traditional NEMS hardly achieve quantum squeezing due to their thickness limits. A scheme to obtain squeezed quantum states through typical experimental graphene NEMS structures taking advantages of its atomic scale thickness has been proposed.
=== Music and the culture industry === Adorno criticized jazz and popular music, viewing it as part of the culture industry that contributes to the present sustainability of capitalism by rendering it "aesthetically pleasing" and "agreeable." In his early essays for the Vienna-based journal Anbruch, Adorno claimed that musical progress is proportional to the composer's ability to constructively address the possibilities and limitations contained within what he called the "musical material." For Adorno, twelve-tone serialism constitutes a decisive, historically developed method of composition. The objective validity of composition, according to him, rests with neither the composer's genius nor the work's conformity with prior standards but with the way in which the work coherently expresses the dialectic of the material. In this sense, the contemporary absence of composers of the status of Bach or Beethoven is not the sign of musical regression; instead, new music is to be credited with laying bare aspects of the musical material previously repressed: The musical material's liberation from number, the harmonic series and tonal harmony. Thus, historical progress is achieved only by the composer who "submits to the work and seemingly does not undertake anything active except to follow where it leads." Because historical experience and social relations are embedded within this musical material, it is to the analysis of such material that the critic must turn.
== Function == The activity of GSTs is dependent upon a steady supply of GSH from the synthetic enzymes gamma-glutamylcysteine synthetase and glutathione synthetase, as well as the action of specific transporters to remove conjugates of GSH from the cell. The primary role of GSTs is to detoxify xenobiotics by catalyzing the nucleophilic attack by GSH on electrophilic carbon, sulfur, or nitrogen atoms of said nonpolar xenobiotic substrates, thereby preventing their interaction with crucial cellular proteins and nucleic acids. Specifically, the function of GSTs in this role is twofold: to bind both the substrate at the enzyme's hydrophobic H-site and GSH at the adjacent, hydrophilic G-site, which together form the active site of the enzyme; and subsequently to activate the thiol group of GSH, enabling the nucleophilic attack upon the substrate. The glutathione molecule binds in a cleft between N- and C-terminal domains - the catalytically important residues are proposed to reside in the N-terminal domain. Both subunits of the GST dimer, whether hetero- or homodimeric in nature, contain a single nonsubstrate binding site, as well as a GSH-binding site. In heterodimeric GST complexes such as those formed by the cytosolic mu and alpha classes, however, the cleft between the two subunits is home to an additional high-affinity nonsubstrate xenobiotic binding site, which may account for the enzymes' ability to form heterodimers.
Sources: en.wikipedia.org
Clomipramine/sildenafil (developmental code name CDFR-0812) is a combination of the tricyclic antidepressant (TCA) and serotonin–norepinephrine reuptake inhibitor (SNRI) clomipramine and the phosphodiesterase PDE5 inhibitor and erectile dysfunction drug sildenafil which is under development for the on-demand treatment of premature ejaculation. It is taken orally. The drug is under development by CTCBIO. As of October 2025, it is in phase 3 clinical trials in South Korea.
=== Professional history and early years in Vermont === After graduating from college, Sanders returned to New York City, where he worked various jobs, including as a Head Start teacher, a psychiatric aide, and a carpenter. In 1968, he moved to Stannard, Vermont, a town small in both area and population (88 residents at the 1970 census) within Vermont's rural Northeast Kingdom region, because he had been "captivated by rural life". While there, he worked as a carpenter, filmmaker, and writer who created and sold "radical film strips" and other educational materials to schools. Sanders wrote articles for The Vermont Freeman. One article later received media attention during his national political career after its contents were rediscovered and reported in the press. He lived in the area for several years before moving to the more populous Chittenden County in the mid-1970s. During his 2018 reelection campaign, he returned to the town to hold an event with voters and other candidates.
Desglymidodrine (developmental code name ST-1059) is the active metabolite of the prodrug antihypotensive agent midodrine. It acts as a selective α1-adrenergic receptor agonist. Desglymidodrine is formed from midodrine via deglycination.
Meanwhile the affected person undergoes myeloablative conditioning, after which the altered HSCs can be infused back, becoming engrafted in the bone marrow where they proliferate. This results in a progressive increase in beta-globin synthesis which improves the balance of alpha and beta globins in all subsequent developing red blood cells. Healthy hemoglobin A is generated resolving the anemia. Exagamglogene autotemcel, sold under the brand name Casgevy, is a gene therapy for the treatment of transfusion-dependent beta thalassemia which induces increased production of fetal hemoglobin HbF. The treatment was approved in the United Kingdom for the treatment of transfusion-dependent beta thalassemia in November 2023 and in the United States in January 2024. Casgevy works by editing the BCL11A gene, which normally inhibits the production of HbF in adults. The edit has the effect of increasing production of gamma globin, a component of fetal hemoglobin HbF, and thereby resolving the anemia.
=== Competition binding === Competition binding is used to determine the presence of selectivity for a particular ligand for receptor sub-types, which allows the determination of the density and proportion of each sub-type in the tissue. Competition curves are obtained by plotting specific binding, which is the percentage of the total binding, against the log concentration of the competing ligand. A steep competition curve is usually indicative of binding to a single population of receptors, whereas a shallow curve, or a curve with clear inflection points, is indicative of multiple populations of binding sites.
Sources: en.wikipedia.org
Tautomerism – A base is changed by the repositioning of a hydrogen atom, altering the hydrogen bonding pattern of that base, resulting in incorrect base pairing during replication. Theoretical results suggest that proton tunneling is an important factor in the spontaneous creation of GC tautomers. Depurination – Loss of a purine base (A or G) to form an apurinic site (AP site). Deamination – Hydrolysis changes a normal base to an atypical base containing a keto group in place of the original amine group. Examples include C → U and A → HX (hypoxanthine), which can be corrected by DNA repair mechanisms; and 5MeC (5-methylcytosine) → T, which is less likely to be detected as a mutation because thymine is a normal DNA base. Slipped strand mispairing – Denaturation of the new strand from the template during replication, followed by renaturation in a different spot ("slipping"). This can lead to insertions or deletions.
Gaddafi was especially critical of the US due to its support of Israel and sided with the Palestinians in the Israeli–Palestinian conflict, viewing the creation of Israel as a Western colonial occupation forced upon the Arab world. He believed Palestinian violence against Israeli and Western targets the justified response of an oppressed people fighting against colonization. Calling on Arab states to wage "continuous war" against Israel, in 1970 he initiated a Jihad Fund to finance anti-Israeli militants. In June 1972 Gaddafi created the First Nasserite Volunteers Centre to train anti-Israeli guerrillas. Like Nasser, Gaddafi favoured the Palestinian leader Yasser Arafat and his group, Fatah, over more militant and Marxist Palestinian groups. As the years progressed however, Gaddafi's relationship with Arafat became strained, with Gaddafi considering him too moderate and calling for more violent action. Instead, he supported militias like the Popular Front for the Liberation of Palestine, Popular Front for the Liberation of Palestine – General Command, the Democratic Front for the Liberation of Palestine, As-Sa'iqa, the Palestinian Popular Struggle Front, and the Abu Nidal Organization. He funded the Black September Organization which perpetrated the 1972 Munich massacre of Israeli athletes in West Germany and flew the militants' bodies to Libya for a hero's funeral. Gaddafi financially supported other militant groups across the world, including the Black Panther Party, the Nation of Islam, the Almighty Black P.
==== Genetically modified organisms (GMOs) ==== Golden rice was a GMO created in 2005 through heterologous expression as a humanitarian effort to address the effects of Vitamin A deficiency. Oryza sativa rice was transfected with a gene to produce β-carotene, a Vitamin A precursor that has a yellow-orange color.
=== Microscopic features === Psilocybe baeocystis spores are dark purplish brown in deposit, oblong in face view or asymmetric ellipsoid (mango form) in side view, and are (8.5) 9.5–13.7(17) x (5) 5.5–6.6(7.1) μm. The basidia are 4-spored, and pleurocystidia are absent. The cheilocystidia are 20–30(40) x 4.5–6(9) μm and fusiod with a narrow neck. This species closely resembles subtropical Psilocybe aztecorum and Psilocybe quebecensis, which also have caps that bleach in color to white when dry.
=== 13 April === The Ukrainian Defence Ministry confirmed that Russian forces had reached the northern outskirts of Bohdanivka, ten kilometers from Chasiv Yar. Russia claimed to have taken Pervomaiske, 11 kilometers west of Avdiivka. Three people were killed in separate Russian attacks in Donetsk Oblast, while two people were killed in Kharkiv Oblast. One person was killed in a Russian attack on a car carrying humanitarian aid in Chernihiv Oblast. The Russian-installed head of Luhansk Oblast claimed that three people were injured in a Ukrainian missile attack on a factory in Luhansk city. Ukrainian officials claimed to have destroyed a major Russian headquarters using Storm Shadow missiles. Russian media later reported that Colonel Pavel Kropotov, commander of the 59th Guards Communications Brigade, was killed in the attack. The SBU announced that it had thwarted an assassination attempt against Kherson Oblast Governor Oleksandr Prokudin, adding that it had arrested a suspect who tried to launch a drone at his car. The IAEA reported that the Zaporizhzhia Nuclear Power Plant had been placed in a state of cold shutdown for the first time since October 2022. Germany announced that it would deliver another Patriot battery and additional missiles to Ukraine.
Sources: en.wikipedia.org
It is a modified version of the natural hormone, with three amino acid changes and a fatty acid side chain added. These edits extend its half-life from minutes to about one week. The core receptor activity is retained.
Both deliver the same active peptide and act on the same receptor. The tablet includes an absorption enhancer because peptides are poorly taken up intact from the gut. Bioavailability of the oral route is substantially lower, so the two are not dose-equivalent.
No, it is entirely synthetic and does not occur in nature. Native GLP-1 is produced in the gut and pancreas, but the analog is manufactured by chemical synthesis or recombinant methods. Traces of the analog are not expected in people who never received it.
It belongs to the incretin mimetic class and acts as a long-acting glucagon-like peptide-1 receptor agonist. The class includes several peptides with different half-lives and routes of administration.