This is a working overview of receptor agonist, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Receptor activation raises intracellular cyclic AMP through Gs coupling, which promotes glucose-dependent insulin release and suppresses glucagon secretion when blood glucose is elevated. Effects outside the pancreas include slower gastric emptying and altered appetite signalling in the hypothalamus and hindbrain. The relative contribution of each tissue to overall metabolic outcomes remains an area of active investigation. Central mechanisms in particular are inferred mainly from animal models and indirect human measures rather than direct observation.
Serum protein binding dominates the pharmacokinetic profile. The attached chain associates strongly with albumin, shielding the peptide from enzymatic attack and slowing filtration by the kidney. This interaction extends the circulation half-life to roughly one week in humans, which supports weekly administration intervals. An oral version pairs the peptide with an absorption enhancer that transiently alters gastric epithelium, permitting limited uptake; bioavailability by that route is substantially lower than by injection.
Semaglutide belongs to the glucagon-like peptide-1 receptor agonist class, a group of synthetic peptides that imitate an incretin hormone released by intestinal L cells after food intake. Native GLP-1 circulates for only a few minutes because dipeptidyl peptidase-4 cleaves it rapidly. The hormone acts on pancreatic islets, the gastrointestinal tract, and several brain regions. Because the natural peptide is short-lived, development work concentrated on analogues that keep receptor activity while resisting enzymatic breakdown and renal clearance.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide, GLP-1 receptor agonist | 31 amino acid residues |
| Molecular formula | C187H291N45O59 | free peptide, no counter-ion |
| Approximate mass | 4114 Da | matches theoretical value |
| Receptor target | Glucagon-like peptide-1 receptor | Gs-coupled, cyclic AMP pathway |
| Circulation half-life | About one week in humans | extended by albumin association |
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 or 280 nanometres is widely used to assess purity and to resolve related impurities. Liquid chromatography coupled to mass spectrometry confirms identity through the protonated molecular ion and fragment ions formed in tandem experiments. Capillary electrophoresis and peptide mapping after enzymatic digestion supply complementary information on charge variants and modification sites. Circular dichroism and nuclear magnetic resonance can report on secondary structure in solution. Absolute quantification usually depends on an external standard, and reported purity depends on the detection wavelength and integration parameters chosen.
Lyophilised material appears as a white to off-white cake or powder that is hygroscopic, and containers are usually equilibrated to room temperature before opening to limit condensation. Dissolution is performed in water, phosphate-buffered saline, or a mildly alkaline buffer, since solubility rises above neutral pH. Gentle inversion or low-speed mixing is preferred, because vigorous vortexing can promote surface denaturation and aggregation. Complete dissolution may require several minutes, and brief sonication is sometimes applied. Passing the solution through a 0.22 micrometre membrane removes particulates but does not by itself sterilise the liquid.
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。
Two structural features account for the prolonged half-life of semaglutide. A modified amino acid at position 8 resists cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GLP-1. A fatty diacid side chain binds serum albumin, which limits renal clearance and protects the peptide from enzymatic breakdown. These modifications yield a plasma half-life of approximately one week in humans, allowing once-weekly administration. The relationship between plasma concentration and clinical effect varies between individuals, and sources of that variability are still being characterized.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1 (GLP-1), a hormone released from intestinal L-cells after food intake. The compound belongs to the incretin mimetic class and acts at GLP-1 receptors distributed across pancreatic, gastrointestinal, cardiovascular, and central nervous system tissues. Compared with native GLP-1, the molecule carries structural changes that extend its activity from minutes to roughly one week. It is studied for glycemic control in type 2 diabetes and for weight management, and its effects on cardiovascular and other outcomes remain active research areas.
Identity theft is a form of fraud or cheating of another person's identity in which someone pretends to be someone else by assuming that person's identity, typically in order to access resources or obtain credit and other benefits in that person's name. Victims of identity theft (those whose identity has been assumed by the identity thief) can suffer adverse consequences if held accountable for the perpetrator's actions, as can organizations and individuals who are defrauded by the identity thief, and to that extent are also victims. Internet fraud refers to the actual use of Internet services to present fraudulent solicitations to prospective victims, to conduct fraudulent transactions, or to transmit the proceeds of fraud to financial institutions or to others connected with the scheme. In the context of organized crime, both may serve as means through which other criminal activity may be successfully perpetrated or as the primary goal themselves. Email fraud, advance-fee fraud, romance scams, employment scams, and other phishing scams are the most common and most widely used forms of identity theft, though with the advent of social networking fake websites, accounts and other fraudulent or deceitful activity has become commonplace.
The Society for Clinical Data Management (SCDM) is an international organization with 2,590 members promoting quality and excellence in data management, and featuring webinars, online courses, certification, and an annual conference. The Association Française de Data Management Biomédicale (DMB) is a French data management organization created in 1995. Gathers data from data managers (anyone involved in data management activity for developing drugs) from the pharmaceutical industry, CROs, software vendors or universities. The French network of data managers in academic biomedical research (AcaDM) is a network founded in 2008 which aims to offer a space for reflection between experts in order to standardize and improve practices.
Statistical potentials, in contrast to physics-based potentials, have the advantage of being fast to compute, of accounting implicitly of complex effects and being less sensitive to small changes in the protein structure. These energy functions are based on deriving energy values from frequency of appearance on a structural database. Protein design, however, has requirements that can sometimes be limited in molecular mechanics force-fields. Molecular mechanics force-fields, which have been used mostly in molecular dynamics simulations, are optimized for the simulation of single sequences, but protein design searches through many conformations of many sequences. Thus, molecular mechanics force-fields must be tailored for protein design. In practice, protein design energy functions often incorporate both statistical terms and physics-based terms. For example, the Rosetta energy function, one of the most-used energy functions, incorporates physics-based energy terms originating in the CHARMM energy function, and statistical energy terms, such as rotamer probability and knowledge-based electrostatics. Typically, energy functions are highly customized between laboratories, and specifically tailored for every design.
Phenibut, sold under the brand name Anvifen among others, is a central nervous system (CNS) depressant with anxiolytic effects, and is used to treat anxiety, insomnia, and for a variety of other indications. It is usually taken orally (swallowed by mouth), but may be given intravenously. Side effects of phenibut can include sedation, sleepiness, nausea, irritability, agitation, dizziness, euphoria, and sometimes headache, among others. Overdose of phenibut can produce marked central nervous system depression including unconsciousness. The medication is structurally related to the neurotransmitter γ-aminobutyric acid (GABA), and hence is a GABA analogue. Phenibut is thought to act as a GABAB receptor agonist, similarly to baclofen and γ-hydroxybutyrate (GHB). However, at low concentrations, phenibut mildly increases the concentration of dopamine in the brain, providing stimulatory effects in addition to the anxiolysis. Phenibut was developed in the Soviet Union and was introduced for medical use in the 1960s. Today, it is marketed for medical use in Russia, Ukraine, Belarus, Kazakhstan, and Latvia. The medication is not approved for clinical use in the United States and most of Europe, but it is sold on the Internet as a supplement and purported nootropic. Phenibut has been used recreationally and can produce euphoria as well as addiction, dependence, and withdrawal. It is a controlled substance in Australia, and it has been suggested that its legal status should be reconsidered in Europe as well.
The new regime was intended to be transitory, but gradually closed in on itself and became a full dictatorship with the promulgation of the Fifth Institutional Act in 1968. Oppression was not limited to those who resorted to guerrilla tactics to fight the regime, but also reached institutional opponents, artists, journalists and other members of civil society, inside and outside the country through "Operation Condor". Like other authoritarian regimes, due to an economic boom, known as the "economic miracle", the Brazilian military dictatorship reached a peak in popularity in the early 1970s. Slowly, however, the wear and tear of years of dictatorial power had not slowed the repression, even after the defeat of the leftist guerrillas. The inability to deal with the economic crises of the period and popular pressure made a redemocratization policy inevitable, which from the regime side was led by Generals Ernesto Geisel and Golbery do Couto e Silva. With the enactment of the Amnesty Law in 1979, Brazil began a slow return to democracy, which was completed during the 1980s.
Sources: en.wikipedia.org
== Chemistry and materials science == Himalayan salt does not have lower levels of sodium than conventional table salt. Glass does not flow at room temperature as a high-viscosity liquid. Although glass shares some molecular properties with liquids, it is a solid at room temperature and begins to flow only at hundreds of degrees above room temperature. Old glass which is thicker at the bottom than at the top comes from the production process, not from slow flow; no such distortion is observed in other glass objects of similar or even greater age. Diamonds are not generally formed from compressed coal. Most natural gem diamonds formed in the conditions of extreme heat and pressure, commonly about 150 to 200 kilometers (93 to 124 mi) below the surface, and were later brought upward by kimberlite eruptions. Coal, by contrast, is a sedimentary deposit formed from buried plant remains, and is unlikely to migrate below 3.2 kilometers (2.0 mi) through geological processes. Because many diamonds are billions of years old, whereas the first land plants appeared much later, coal was not the source material for most natural diamonds. Neither "tin" foil nor "tin" cans still use tin as a primary material. Aluminum foil has replaced tin foil in almost all uses since the 20th century; tin cans now primarily use steel or aluminum as their main metal. There is no special compound added to the water in swimming pools that will reveal the presence of urine and catch those who urinate in the pool.
Desloratadine exhibits only peripheral activity since it does not readily cross the blood–brain barrier; hence, it does not normally cause drowsiness because it does not readily enter the central nervous system. Desloratadine does not have a strong effect on a number of tested enzymes in the cytochrome P450 system. It was found to weakly inhibit CYP2B6, CYP2D6, and CYP3A4/CYP3A5, and not to inhibit CYP1A2, CYP2C8, CYP2C9, or CYP2C19. Desloratadine was found to be a potent and relatively selective inhibitor of UGT2B10, a weak to moderate inhibitor of UGT2B17, UGT1A10, and UGT2B4, and not to inhibit UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, UGT2B15, UGT1A7, and UGT1A8.
In March 2001 the license for Trovan was withdrawn in Europe, by the European Commission due to liver toxicity and some deaths. In June 2010, the US Supreme Court rejected Pfizer's appeal against a ruling allowing lawsuits by the Nigerian families to proceed. In December 2010, the United States diplomatic cables leak indicated that Pfizer hired investigators to find evidence of corruption against Nigerian attorney general Michael Aondoakaa to persuade him to drop legal action. The Washington Post reporter Joe Stephens, who helped break the story in 2000, called these actions "dangerously close to blackmail". In response, the company released a press statement describing the allegations as "preposterous" and saying that it acted in good faith. Aondoakka, who had allegedly demanded bribes from Pfizer in return for a settlement of the case, was declared unfit for office and had his U.S. visa revoked in association with corruption charges in 2010. The lawsuits were eventually settled out of court. Pfizer committed to paying US$35 million "to compensate the families of children in the study", another $30 million to "support healthcare initiatives in Kano", and $10 million to cover legal costs. Payouts began in 2011.
There is a general chain of events that applies to infections, sometimes called the chain of infection or transmission chain. The chain of events involves several steps – which include the infectious agent, reservoir, entering a susceptible host, exit and transmission to new hosts. Each of the links must be present in a chronological order for an infection to develop. Understanding these steps helps health care workers target the infection and prevent it from occurring in the first place.
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Sources: en.wikipedia.org
It is a synthetic peptide of 31 amino acids, built to resemble the natural incretin hormone GLP-1. Because of its size and composition it is handled analytically like other therapeutic peptides, using chromatographic and mass spectrometric methods rather than the techniques typical of small organic drugs.
The substitution at position 8 removes the site recognised by dipeptidyl peptidase-4, the enzyme that destroys the native hormone within minutes. The linked lipophilic chain then binds circulating albumin, which further limits access by degradative enzymes and reduces renal loss. Together these features lengthen the effective circulation time considerably.
It acts at the glucagon-like peptide-1 receptor, a G protein-coupled receptor that signals mainly through cyclic AMP. Activation is glucose dependent, meaning insulin release is stimulated more strongly when blood glucose is already elevated. Other tissues carrying the same receptor respond as well, which explains effects beyond glucose control.
It is a glucagon-like peptide-1 receptor agonist, often grouped with the incretin mimetics. Its backbone is modified from the human hormone to resist enzymatic degradation and to bind albumin. These two features distinguish it from the native peptide.