The short version of GLP-1 receptor 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.
Both receptors are class B G protein-coupled receptors that signal largely through Gs-mediated cyclic AMP production. Activation within pancreatic islets increases glucose-dependent insulin secretion and suppresses glucagon release when glucose is elevated. Outside the pancreas, signaling in the central nervous system and gut appears to influence appetite and gastric emptying. The relative contribution of each receptor to observed clinical effects remains under investigation, and the two pathways are not simply additive in practice.
Reported outcomes in large trials include dose-dependent weight reduction and improvements in glycemic markers over periods ranging from several months to more than a year. Whether the compound alters long-term cardiovascular or renal outcomes is being examined in dedicated outcome studies, so those questions remain open. Labeling describes gastrointestinal effects such as nausea and diarrhea, which tend to appear during dose escalation. Discontinuation rates and the durability of effects after treatment stops vary across study populations and are still debated.
Tirzepatide is a synthetic peptide developed as a dual agonist at the glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors. Its structure is built on a GIP-derived backbone with non-natural amino acid substitutions and a fatty diacid side chain that promotes albumin binding and slows clearance. That modification supports once-weekly subcutaneous dosing. Registrational trial programs reported reductions in body weight and glycated hemoglobin alongside the drug's glycemic effects.
定量分析的主流方法是反相高效液相色谱联用紫外或质谱检测，利用肽在疏水固定相上的保留行为确定纯度与含量。对于生物基质中的浓度测定，常采用液相色谱串联质谱，并配合固相萃取或蛋白沉淀进行样品前处理。免疫分析法也可使用，但可能受到结构相关肽的交叉反应干扰。
纯度评估通常综合反相色谱、体积排阻色谱与质谱三方面信息：前者反映疏水性杂质，后者反映聚集体，质谱则确认分子量与主要降解产物。有关降解途径的完整图谱——例如脱酰胺、氧化与水解各占多大比例——在不同储存条件下仍有差异，属于需要逐案验证的问题。
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic 39-residue peptide | GIP-derived backbone with non-natural residues |
| Molar mass | Approximately 4.8 kDa | Peptide chain plus linker and lipid modifications |
| Appearance | White to off-white powder | Typical of lyophilized research material |
| Solubility | Soluble in water and aqueous buffer | Practically insoluble in nonpolar solvents |
| Storage temperature | Typically −20 °C for dry powder | Solutions usually held at 2–8 °C short term |
The peptide shares degradation routes common to modified peptides: deamidation of asparagine and glutamine residues, oxidation of methionine, and backbone hydrolysis under extreme pH. Lyophilized material is generally more stable than a solution, and residual water content directly affects the rate of hydrolysis. In liquid form, aggregation and visible particles can appear after agitation or repeated freeze-thaw cycles. Stability studies therefore track monomer content, aggregate content, and potency over months under defined temperature and humidity.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Tirzepatide is a synthetic peptide composed of 39 amino acids. It acts as a dual agonist at two incretin receptors, the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. The molecule was designed by modifying the native sequence of glucose-dependent insulinotropic polypeptide to improve metabolic stability and extend its circulation time. Its structure includes several non-natural amino acid residues and a fatty acid side chain. These features distinguish it from earlier single-receptor incretin analogs studied in the same period.
The compound first appeared in the scientific literature as an investigational agent for type 2 diabetes. Clinical development proceeded through phase 1, phase 2, and phase 3 programs that measured glycemic control as a primary endpoint while recording body weight as a secondary outcome. Regulatory approval in the United States followed in 2022 for glycemic control, and a separate indication for chronic weight management was added later. Subsequent trials have examined cardiovascular outcomes in adults with elevated cardiovascular risk. Debates continue over how much of the observed effect derives from each receptor arm.
Dual agonism at the GIP and GLP-1 receptors underlies the observed pharmacology. Activation of GLP-1 receptors raises glucose-dependent insulin release, lowers glucagon secretion, slows gastric emptying and reduces appetite. GIP receptor activation contributes additional effects on adipose tissue and on energy balance, and the combined action on appetite appears larger than either pathway alone in animal models. Signalling bias and the relative contribution of each receptor arm to weight-related effects remain areas of active investigation.
Structure-activity work shows that fatty acid length, linker chemistry and the position of acylation all influence albumin affinity and receptor potency. Plasma protein binding exceeds 99 percent, which restricts distribution and slows renal clearance. Degradation proceeds largely through general proteolysis and fatty acid oxidation rather than cytochrome P450 metabolism, so exposure to common oxidative drug interactions is limited. Whether these clearance routes vary meaningfully between individuals is not fully established.
The molecule is a synthetic 39-amino-acid peptide whose backbone derives from the sequence of human glucose-dependent insulinotropic polypeptide, with several substitutions that raise metabolic stability and shift receptor preference. A C20 fatty diacid is attached through a short linker to a lysine side chain, a modification that increases binding to serum albumin. The reported monoisotopic mass is approximately 4813 Da. Near neutral pH the peptide carries a net negative charge, and the lipid tail makes the molecule markedly more hydrophobic than the unmodified parent sequence.
Peptide active ingredients of this type are typically supplied as lyophilized powder because the dry form resists hydrolysis during transport. The material is hygroscopic, so vials are usually equilibrated to room temperature before opening to avoid condensation on the solid. Repeated freeze-thaw cycles can promote aggregation and are generally avoided by aliquoting stock into single-use portions. Personnel handling the powder work in controlled environments to limit inhalation of fine particles. Written procedures usually specify these steps rather than leaving them to individual judgment.
Long-term storage of the solid generally relies on temperatures at or below minus twenty degrees Celsius, while short-term working stocks may be held refrigerated. Light exposure is limited because photodegradation can alter side chains over extended periods. Solutions prepared for analysis are less stable than the dry powder and are typically used within the same working day. Buffer choice matters, since some aqueous conditions favor deamidation or oxidation at specific residues. Stability data are usually generated under defined accelerated conditions and then extrapolated with stated assumptions.
Identity and purity are established with reversed-phase high-performance liquid chromatography, often paired with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion verifies the primary sequence and detects substitutions. Size-exclusion chromatography quantifies aggregates and fragments, which are the impurities most often tracked for peptides of this size. Residual solvents, counterions, and water content fall under separate tests described in pharmacopeial chapters. Circular dichroism or nuclear magnetic resonance may be used in research settings to probe secondary structure, though such methods are less common in routine release testing.
== Origin == Whenever muscles and joints are moved this also exerts mechanical strain on related fascia. The general assumption in sports science had therefore been that muscle strength exercises as well as cardiovascular training would be sufficient for an optimal training of the associate fibrous connective tissues. However, recent ultrasound-based research revealed that the mechanical threshold for a training effect on tendinous tissues tends to be significantly higher than for muscle fibers. This insight happened roughly during the same time in which the field of fascia research attracted major attention by showing that fascial tissues are much more than passive transmitters of muscular tension (years 2007 – 2010). Both influences together triggered an increasing attention in sports science towards the question whether and how fascial tissues can be specifically stimulated with active exercises. Researchers who contributed to the initial scientific investigation of this direction include Robert Schleip, Jan Wilke, Michael Kjaer and Adamantios Arampatzis.
Inside of the prostate, adjacent and parallel to the prostatic urethra, there are two longitudinal muscle systems. On the front side (ventrally) runs the urethral dilator (musculus dilatator urethrae), on the backside (dorsally) runs the muscle switching the urethra into the ejaculatory state (musculus ejaculatorius).
Studies show that the EPOC effect exists after both aerobic exercise and anaerobic exercise. In a 1992 Purdue study, results showed that high intensity, anaerobic type exercise resulted in a significantly greater magnitude of EPOC than aerobic exercise of equal work output. For exercise regimens of comparable duration and intensity, aerobic exercise burns more calories during the exercise itself, but the difference is partly offset by the higher increase in caloric expenditure that occurs during the EPOC phase after anaerobic exercise. Anaerobic exercise in the form of high-intensity interval training was also found in one study to result in greater loss of subcutaneous fat, even though the subjects expended fewer than half as many calories during exercise. Whether this result was caused by the EPOC effect has not been established, and the caloric content of the participants' diet was not controlled during this particular study period. Most researchers use a measure of EPOC as a natural part of the quantification or measurement of exercise and recovery energy expenditure; to others this is not deemed necessary. After a single bout or set of weight lifting, Scott et al. found considerable contributions of EPOC to total energy expenditure. In their 2004 survey of the relevant literature, Meirelles and Gomes found: "In summary, EPOC resulting from a single resistance exercise session (i.e., many lifts) does not represent a great impact on energy balance; however, its cumulative effect may be relevant".
Also, during the 1981 tour, veteran session drummer Andy Newmark stepped in briefly for Knudsen, who was then in rehab. And by the end of 1981, even Simmons had left the band. Now with no remaining original members and a "leader" in McDonald who was ready for a solo career, the group elected instead to disband after a rehearsal without Simmons, according to an interview with McDonald for Listen to the Music, the Doobie Brothers' official video history/documentary released in 1989. He went on to say that by that point they could not have gotten further away from the Doobies sound if they had tried. Simmons, already at work on his first solo album, Arcade, rejoined for a 1982 farewell tour on the condition that this truly would be the end of the Doobie Brothers. At their last concert at the Greek Theatre in Berkeley, California, on September 11, 1982, they were joined onstage by founding member Tom Johnston for what was presumed to be the final rendition of his staple, "China Grove". Former members Porter, Hossack and Hartman subsequently took the stage for an extended version of "Listen to the Music". Knudsen sang lead vocals while Johnston, Simmons and McFee traded licks on guitar. The live album Farewell Tour was released in 1983 and the Greek Theatre concert was released in 2011 as Live at the Greek Theatre 1982.
The lack of harmful effects on the patient and the operator make MRI well-suited for interventional radiology, where the images produced by an MRI scanner guide minimally invasive procedures. Such procedures use no ferromagnetic instruments. A specialized growing subset of interventional MRI is intraoperative MRI, in which an MRI is used in surgery. Some specialized MRI systems allow imaging concurrent with the surgical procedure. More typically, the surgical procedure is temporarily interrupted so that MRI can assess the success of the procedure or guide subsequent surgical work.
Sources: en.wikipedia.org
Cresswell and co-workers first discovered tapasin (TAP-associated glycoprotein) as a 48 kDa protein in complexes isolated with TAP1 antibodies from digitonin lysates of human B lymphoblastoid cells. Tapasin binds HC/β2m along with ER chaperones to the peptide transporter. It is located in the ER and its function comprises holding together class I molecules jointly with the chaperone calreticulin and the ERp57 to TAP. Studies of a tapasin-deficient cell line and from mice bearing a disrupted tapasin gene, the short-lived complex of class I molecules. Tapasin and TAP are very important for the stabilization of the class I molecules and also for the optimization of the peptide presented to cytotoxic T cells. A PLC-independent tapasin homologue protein named TAPBPR was found that has the ability to act as a second MHC-I specific peptide proofreader or editor, but does not possess a transmembrane domain. Tapasin and TAPBPR share similar binding interfaces on MHC-I, as shown with the X-ray structure of TAPBPR with MHC-I (heavy chain and β2 microglobulin). The use of a photo-cleavable high-affinity peptide allowed researchers to form a stable (bound) MHC-I molecules and afterwards to form a stable TAPBPR and MHC-I complex with cleavage by UV light of the photoinduced peptide.
Acrodermatitis chronica atrophicans (Herxheimer disease, primary diffuse atrophy) Actinic elastosis (solar elastosis) Anetoderma (anetoderma maculosa, anetoderma maculosa cutis, atrophia maculosa cutis, macular atrophy) Blepharochalasis Cutis laxa (chalazoderma, dermatochalasia, dermatolysis, dermatomegaly, generalized elastolysis, generalized elastorrhexis, pachydermatocele) Cutis rhomboidalis nuchae Ehlers–Danlos syndrome (cutis hyperelastica, elastic skin, India rubber skin) Elastosis perforans serpiginosa Homocystinuria Jadassohn–Pellizzari anetoderma Linear focal elastosis (elastotic striae) Loeys–Dietz syndrome Marfan syndrome Occipital horn syndrome Osteogenesis imperfecta (Lobstein syndrome) Perforating calcific elastosis (localized acquired cutaneous pseudoxanthoma elasticum, perforating periumbilical calcific elastosis, periumbilical perforating pseudoxanthoma elasticum) Pseudoxanthoma elasticum (Grönblad–Strandberg syndrome) Reactive perforating collagenosis Schweninger–Buzzi anetoderma Sclerotic fibroma Striae atrophicans Striae distensae Ullrich disease Verrucous perforating collagenoma Wrinkly skin syndrome
=== Among male homosexuals === A study undertaken at Utrecht University found that the majority of gay men in the study regarded a large penis as ideal, and having one was linked to self-esteem. One study analysing the self-reported Kinsey data set found that the average penis of a homosexual man was larger than the average penis of their heterosexual counterparts (6.32 inches [16.05 cm] in length amongst gay men versus 5.99 in [15.21 cm] in heterosexuals, and 4.95 inches [12.57 cm] circumference amongst gay men versus 4.80 in [12.19 cm] in heterosexual men).
Captain John Macarthur: pioneer of the Merino wool industry in Australia, founder of the Australian Agricultural Company, and large landowner at Camden. Captain William Cox: builder of the road across the Blue Mountains, important pastoralist in the Hawkesbury and Bathurst regions. Captain John Piper: significant land-holder in Sydney and Bathurst. Captain Edward Abbott: important colonist of Tasmania. Lieutenant William Lawson: explorer across the Blue Mountains and prominent land-holder in the Mudgee region. Lieutenant Anthony Fenn Kemp: significant colonist of Tasmania. Lieutenant Archibald Bell Sr.: important landowner in the Hawkesbury region. Surgeon John Harris: extensive property owner in Sydney and the Bathurst region. Lieutenant Nicholas Bayly: large land-holder in Cabramatta region.
Sources: en.wikipedia.org
== Structure == 50S, roughly equivalent to the 60S ribosomal subunit in eukaryotic cells, is the larger subunit of the 70S ribosome of prokaryotes. The 50S subunit is primarily composed of proteins but also contains single-stranded RNA known as ribosomal RNA (rRNA). rRNA forms secondary and tertiary structures to maintain the structure and carry out the catalytic functions of the ribosome. X-ray crystallography has yielded electron density maps allowing the structure of the 50S in Haloarcula marismortui (archaeon) to be determined to 2.4Å resolutionand of the 50S in the Deinococcus radiodurans (bacterium) to 3.3Å. The large ribosomal subunit (50S) is approximately twice as massive as the small ribosomal subunit (30S). The model of Hm 50S, determined in 2000 by Nenad Ban and colleagues in the laboratory of Thomas Steitz and the laboratory of Peter Moore, includes 2711 of the 2923 nucleotides of 23S rRNA, all 122 nucleotides of its 5S rRNA, and structure of 27 of its 31 proteins.
=== In antiquity === Emperor Ashoka, who ruled the Maurya Empire in the Indian subcontinent from 269 to 232 BCE, abolished the slave trade but not slavery. The Qin dynasty, which ruled China from 221 to 206 BCE, abolished slavery and discouraged serfdom. However, many of its laws were overturned when the dynasty was overthrown. Slavery was again abolished by Wang Mang in China in 17 CE but was reinstituted after his assassination.
== Finance minister == FinanceAsia for the second year running has ranked the finance ministers of the Asia-Pacific region's 12 largest economies. In the 2016 ranking, Thailand's Apisak Tantivorawong was ranked 11th (1=best, 12=worst). Ranked worst was Malaysia's Najib Razak.
Sources: en.wikipedia.org
It acts as an agonist at both the GIP and GLP-1 receptors, two related class B G protein-coupled receptors. This dual activity distinguishes it from single-receptor GLP-1 agonists. The clinical consequences of engaging both receptors are still being characterized.
It is given by subcutaneous injection, generally on a weekly schedule. Dosing usually begins low and increases in steps to limit gastrointestinal side effects. Formulated product is supplied as a ready-to-use pen or vial in most markets.
No. Receptor engagement is documented, but how central appetite circuits, gut signals, and insulinotropic effects combine is incompletely resolved. Investigators continue to separate GIP-driven from GLP-1-driven contributions in animal and human models.
建议在低温、避光、干燥环境中密封保存，常见条件为 2 至 8 摄氏度，长期存放可置于更低温度。应避免反复冻融，并尽量减少容器开启次数。