This is a working overview of incretin receptor, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-09 and is reviewed periodically as new material appears.
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。
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.
Structural work on the molecule centers on a C20 fatty diacid moiety attached through a linker to the peptide backbone. This side chain promotes reversible binding to serum albumin, which slows renal clearance and supports a prolonged action profile. The peptide backbone incorporates aminoisobutyric acid substitutions that limit recognition by digestive enzymes. Together these modifications produce a molecule that is stable enough for subcutaneous delivery but still dependent on careful manufacturing control. Analytical characterization of the active pharmaceutical ingredient typically follows the conventions used for other synthetic peptides.
| Property | Value | Notes |
|---|---|---|
| 储存温度 | 2 至 8 摄氏度 | 固体粉末，避光密封 |
| 外观 | 白色至类白色冻干粉 | 溶解后为澄清至微乳光 |
| 溶解性 | 易溶于水性缓冲液 | 避免剧烈振荡 |
| 常规纯度方法 | 反相高效液相色谱 | 紫外或质谱检测 |
| 定量方法 | 液相色谱串联质谱 | 配合固相萃取前处理 |
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.
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.
Clinical development proceeded through large phase 3 programmes in type 2 diabetes and in obesity or overweight with at least one weight-related comorbidity. Regulatory approvals followed in several jurisdictions for both indications. Weekly subcutaneous dosing reflects an elimination half-life of roughly five days. Open questions include the durability of metabolic effects after treatment stops, long-term cardiovascular and hepatic outcomes beyond completed trials, and whether the dual mechanism confers benefits independent of total receptor occupancy. Published literature continues to expand on these points. Substantial uncertainty remains about interindividual variability in response.
Tirzepatide is a synthetic linear peptide of 39 amino acids that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Its sequence derives from native GIP but incorporates non-natural residues and a C20 fatty diacid moiety linked to a lysine side chain. The lipophilic chain promotes albumin binding, which slows renal clearance and extends circulation time. The unmodified peptide has a molecular formula of C225H348N48O68 and a molecular mass near 4,813 daltons.
Receptor activation by tirzepatide raises intracellular cyclic AMP through Gs-coupled signalling at both targets. At the GLP-1 receptor the downstream effect includes glucose-dependent insulin release, suppressed glucagon secretion, delayed gastric emptying, and reduced appetite signalling in the hypothalamus. GIP receptor engagement adds insulinotropic activity and appears to influence lipid handling in adipose tissue. Because both receptors are stimulated at the same time, the pharmacological profile differs from that of selective GLP-1 receptor agonists, and the relative contribution of each arm remains an area of active investigation.
Following months of rumours and investigations, on 13 August 2013, Reid—along with the Essendon Football Club, senior coach James Hird, senior assistant coach Mark Thompson, and football manager Danny Corcoran—was charged by the AFL with bringing the game into disrepute in relation to the supplements program at the club in 2011 and 2012. The club was given 14 days to consider the charges and face an AFL Commission hearing on 26 August 2013. On 27 August 2013, the AFL Commission handed down its decision to exclude Essendon from the 2013 finals series and fine it $2 million. James Hird was banned for 12 months, Danny Corcoran suspended for six months, and Mark Thompson fined $30,000, but the case against Reid continued after his decision to fight the charges against him. On 18 September 2013, 24 hours before Reid was due back in the Supreme Court, the AFL withdrew all 38 charges against him for his role in the supplements scandal, meaning he was free to resume his work at the Essendon Football Club.
Dapoxetine, sold under the brand name Priligy among others, is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of premature ejaculation (PE) in men ages 18 to 64 years old. Dapoxetine works by inhibiting the serotonin transporter, increasing serotonin's action at the postsynaptic cleft, and as a consequence promoting ejaculatory delay. As a member of the SSRI family, dapoxetine was initially created as an antidepressant. However, unlike other SSRIs, dapoxetine is absorbed and eliminated rapidly in the body. Its fast-acting property makes it suitable for the treatment of PE, but not as an antidepressant. Originally created by Eli Lilly pharmaceutical company, dapoxetine was sold to Johnson & Johnson in 2003 and submitted as a New Drug Application to the US Food and Drug Administration (FDA) for the treatment of PE in 2004. Dapoxetine is sold in several European and Asian countries, and in Mexico. In the US, dapoxetine has been in phase III development. In May 2012, US-based Furiex Pharmaceuticals reached an agreement with ALZA Corp and Janssen Pharmaceuticals to market dapoxetine in the United States, Japan, and Canada, while selling the rights to market the drug in Europe, most of Asia, Africa, Latin America, and the Middle East to Menarini.
Approximately 70% of the far side was captured; however, on October 7, only 17 of the 29 photos successfully transmitted back to Earth due to issues with signal strength. On October 22, further contact with Luna 3 was lost. November: The Rwandan Revolution begins.
Sources: en.wikipedia.org
=== Otto Mostyn === Otto Mostyn (Roger Barclay) is Henry's godfather, and a fellow classmate of Charles Hanani from Oxford alongside Norton. A sinister, calculating businessman, Otto takes interest in Harper due to her cunning and ruthlessness, and agrees to provide seed funding to LeviathanAlpha, the hedge fund she is starting with Petra Koenig. Otto, Norton, and Aurore are also in a secret cabal to advance their interests via the government. Petra calls Otto after learning that Harper committed insider trading by acting on confidential information she overheard to short Pierpoint. Otto summons Harper to a meeting, where instead of reprimanding her, he tells her he wants her to succeed him in running his investment fund. Harper and Petra ultimately decide to call off the short and end their partnership with Otto to keep their fund above-board, but Harper later teams up with Otto to start her own fund dedicated to shorting corrupt companies over whom she and Otto would have leverage. In series 4, Otto becomes a member of the House of Lords and hopes to obtain a peerage. He puts increasingly strict constraints on Harper's trades at his fund, not wanting her to jeopardize his political connections; she eventually cuts ties with Otto. At Henry's 40th birthday party, Otto receives oral sex from Cordelia, Yasmin's aunt and Charles' sister; it is revealed he also received sexual favors from Charles.
== Regulation == While infant formula is highly regulated in many countries, baby bottles are not. Only the materials of the teat and bottle itself are specifically regulated in some countries (e.g. British Standards BS 7368:1990 "Specification for babies' elastomeric feeding bottle teats"). In the US, the Food and Drug Administration (FDA) regulates teats and the bottle materials. In 1985 the FDA restricted allowable levels of nitrosamines (many of which are carcinogens) released from bottle teats. Tests of bottle nipples available in the US, Singapore, West Germany, England, Japan and Korea suggest that levels of nitrosamines in most rubber baby bottle teats are within recommended standards. Another chemical that has been regulated is Bisphenol A (BPA), described as an endocrine disruptor in 1991. Ongoing research into the possible effects of BPA at levels of exposure far below the U.S. government's BPA safety standards has led to concerns about the safety of plastics, including baby bottles. A 1999 Consumer Reports study showed that some polycarbonate baby bottles released unsafe amounts of BPA. Concerns about BPA have been supported by further work. (Research into the effects of BPA has frequently been hotly contested and controversial and issues have been raised over research biases due to industry funding and conflicts of interest due to close ties between government consultants and BPA manufacturers.) One result has been proposals to change the testing paradigm for assessment of endocrine-disrupting chemicals.
== Characteristics == The NAPEPLD cDNA sequence predicts 396 amino acid sequences in both mice and rats, which are 89% and 90% identical to that of humans. NAPE-PLD was found to have no homology to the known phospholipase D genes, but can be classed by homology to fall into the zinc metallohydrolase family of the beta-lactamase fold. In particular, the highly conserved motif HX(E/H)XD(C/R/S/H)X50–70HX15–30(C/S/D)X30–70H was observed, which is, in general, associated with zinc binding and hydrolysis reaction in this class of proteins, leading the authors to propose that activity should be correlated with zinc content. When recombinant NAPE-PLD was tested in COS cells in vitro it had similar activity toward several radiolabeled substrates: N-palmitoylphosphatidylethanolamine, N-arachidonoylphosphatidylethanolamine, N-oleoylphosphatidylethanolamine, and N-stearoylphosphatidylethanolamine all reacted with a Km between 2–4 micromolar and a Vmax between 73 and 101 nanomole per milligram per minute as calculated by Lineweaver–Burk plot. (These generate N-palmitoylethanolamine, anandamide, N-oleoylethanolamine, and N-stearoylethanolamine, respectively) The enzyme also reacted N-palmitoyl-lyso-phosphatidylethanolamine and N-arachidonoyl-lyso-phosphatidylethanolamine with similar Km but at one-third to one-fourth the Vmax. These activities are consistent with the observation that many tissues produce a range of N-acylethanolamines.
Neomorphic mutations are a part of the gain-of-function mutations and are characterized by the control of new protein product synthesis. The newly synthesized gene normally contains a novel gene expression or molecular function. The result of the neomorphic mutation is the gene where the mutation occurs has a complete change in function. A reversion (or back mutation) is a point mutation that restores the original sequence and hence the original phenotype.
Sources: en.wikipedia.org
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。
溶解后的稳定时间通常短于固体形态，受浓度、缓冲液和容器材质影响。冷藏条件下一般只能维持较短时间，具体期限应通过实际稳定性实验确认。
反相高效液相色谱用于纯度与含量测定，液相色谱串联质谱用于生物基质中的定量，体积排阻色谱用于检测聚集体。多种方法结合才能较完整地表征样品。
It activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. This dual activity separates it from agents that act on only one of the two receptors. The relative contribution of each receptor to clinical effects remains an open area of study.