Everything below concerns 脂肪酸侧链. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
当前公开资料把 tirzepatide 归为肠促胰素类受体双重激动剂。它并非激素天然变体，而是经过序列改造的工程化肽。其分子量、等电点与疏水性等基础参数已在药典和化学数据库中收录，可作为分析检测和质量研究的参照。
Tirzepatide 是一种由 39 个氨基酸组成的合成肽，分子结构上以 GIP 序列为骨架并引入脂肪酸侧链修饰，使其能够同时与葡萄糖依赖性促胰岛素多肽（GIP）受体和胰高血糖素样肽-1（GLP-1）受体结合。这种双重激动特性使它在同类肽类药物中区别于选择性 GLP-1 受体激动剂。该分子最早由一家制药公司在 2010 年代报道，随后进入糖尿病与体重管理领域的临床研究。
Purified material is typically handled as a lyophilized powder kept at or below minus twenty degrees Celsius, shielded from light and moisture. In that state the solid remains stable for extended periods, although repeated freeze-thaw cycling can encourage aggregation. Once dissolved, aqueous solutions are less durable and are generally held cold and used within a brief window. Buffer composition, pH and ionic strength all influence degradation rates, and mildly acidic to neutral conditions are commonly examined. Actual shelf life depends on formulation, concentration and container, so stability limits are established experimentally rather than assumed.
Verification of research-grade material involves checking purity, sequence and counter-ion content against a certificate of analysis. Reported purity figures usually reflect chromatographic area percentage and do not by themselves establish biological activity. Independent laboratories may repeat mass confirmation and peptide mapping to detect substitutions or truncations. Open questions concern how residual solvents, trace metals and subtle conformational variants affect measured behavior, and how consistently different suppliers define their specifications. Documentation of analytical methods matters as much as the headline purity number when results are compared across studies.
| Property | Value | Notes |
|---|---|---|
| 分子类型 | 合成修饰肽 | 39 个氨基酸，含脂肪酸侧链 |
| 受体靶点 | GIP 与 GLP-1 受体 | 双重激动剂 |
| 分子量 | 约 4.8 kDa | 以游离肽计 |
| 外观 | 白色至类白色粉末 | 冻干形态常见 |
| 溶解性 | 可溶于水及水性缓冲液 | 溶解后宜低温保存 |
The peptide backbone contains 39 amino acids and includes alpha-aminoisobutyric acid residues, which are not among the standard proteinogenic set. A C20 fatty diacid moiety is attached through a linker, allowing the compound to bind serum albumin and extend its circulation time. This albumin binding is the main reason the molecule supports once-weekly administration rather than more frequent dosing. The measured molecular mass is approximately 4,813 daltons, placing it firmly in the peptide rather than small-molecule class.
Tirzepatide is a synthetic peptide that activates both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This dual agonist profile distinguishes it from earlier incretin-based compounds that act on a single receptor. The molecule was engineered from the native GIP sequence and carries several non-natural residues that slow enzymatic breakdown. Researchers designed it to combine the insulinotropic effects of GIP signaling with the appetite and gastric-emptying effects associated with GLP-1 activation.
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.
Solid tirzepatide is handled as a lyophilised, hygroscopic peptide powder that should be kept desiccated, protected from light, and stored frozen, typically at or below minus twenty degrees Celsius for long-term retention. Material left at ambient temperature for extended periods can take up moisture, which promotes aggregation and deamidation. Commercial liquid presentations are kept refrigerated between two and eight degrees Celsius and are not frozen. Reconstituted laboratory solutions are generally held cold and used within a short window because hydrolysis and oxidation continue slowly in solution.
Identity and purity are usually established with reversed-phase high-performance liquid chromatography for the main peak and with mass spectrometry for the observed molecular mass. Peptide mapping after enzymatic digestion confirms the primary sequence, while amino acid analysis provides a quantitative composition check. Size-exclusion chromatography and ion-exchange chromatography are used to look for aggregates and charge variants. Water content, residual solvents, and counter-ion content are measured separately, since a lyophilised powder is often reported on an as-is basis unless a correction is applied.
The GIP receptor is expressed in pancreatic islets, adipose tissue, and the central nervous system, while GLP-1 receptors are found in pancreatic islets, the gastrointestinal tract, and the brain. Activation of both receptors can enhance glucose-dependent insulin secretion and reduce glucagon release. The relative contribution of each receptor to the overall pharmacological effect remains an area of ongoing investigation. Preclinical studies suggest that GIP receptor agonism may modulate appetite and energy balance, but the precise mechanisms in humans are not fully established.
In clinical research, tirzepatide has been studied in randomized controlled trials for glycemic control and body weight reduction. These trials typically measure changes in hemoglobin A1c and body weight over periods of several months. The drug is administered by subcutaneous injection, and its pharmacokinetic profile supports once-weekly dosing. Post-marketing surveillance continues to evaluate long-term outcomes and rare adverse events.
Tirzepatide is a synthetic peptide that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. The molecule contains 39 amino acids and features a C20 fatty diacid moiety attached via a linker, which promotes albumin binding and extends its circulating half-life. Its sequence incorporates non-natural amino acids and modifications that reduce susceptibility to degradation by dipeptidyl peptidase-4. This dual receptor activity distinguishes it from selective GLP-1 receptor agonists.
Shaka was the illegitimate son of Senzangakhona, Chief of the Zulus. He was born c. 1787. He and his mother, Nandi, were exiled by Senzangakhona, and found refuge with the Mthethwa. Shaka fought as a warrior under Dingiswayo, leader of the Mthethwa Paramountcy. When Senzangakona died, Dingiswayo helped Shaka become king of the Zulu. After Dingiswayo's death at the hands of Zwide, king of the Ndwandwe, around 1816, Shaka assumed leadership of the entire Mthethwa alliance. Shaka expanded the Zulu Kingdom through war and diplomacy. Shaka's clan at first numbered no more than a few thousands, but eventually grew in size to 45,000 after absorbing neighbouring clans. His military reforms included new battle techniques, training, and tough discipline, as well as the replacement of long throwing spears in exchange for the more effective short stabbing spears. Conscripted men were segregated from the rest of Zulu society to be trained as an organised standing army called the amabutho. The alliance under his leadership survived Zwide's first assault at the Battle of Gqokli Hill (1818). Within two years, Shaka had defeated Zwide at the Battle of Mhlatuze River (1820) and broken up the Ndwandwe alliance. The Ngoni people fled as far north as Tanzania and Malawi. By 1822, Shaka had conquered an empire covering an area of around 80,000 square miles (210,000 km2), covering Pongola to the Tugera Rivers.
=== Costs === At between US$6,000 and $10,000 for a typical treatment, BMPs can be costly compared with other techniques such as bone grafting. However, this cost is often far less than the costs required with orthopaedic revision in multiple surgeries. While there is little debate that rhBMPs are successful clinically, there is controversy about their use. It is common for orthopedic surgeons to be paid for their contribution to the development of a new product, but some of the surgeons responsible for the original Medtronic-supported studies on the efficacy of rhBMP-2 have been accused of bias and conflict of interest. For example, one surgeon, a lead author on four of these research papers, did not disclose any financial ties while with the company on three of the papers; he was paid over $4 million by Medtronic. In another study, the lead author did not disclose any financial ties to Medtronic; he was paid at least $11 million by the company. In a series of 12 publications, the median financial ties of the authors to Medtronic were $12–16 million. In those studies that had more than 20 and 100 patients, one or more authors had financial ties of $1 million and $10 million, respectively. Early clinical trials using rhBMP-2 underreported adverse events associated with treatment. In the 13 original industry-sponsored publications related to safety, there were zero adverse events in 780 patients. It has since been revealed that potential complications can arise from the use including implant displacement, subsidence, infection, urogenital events, and retrograde ejaculation.
Furthermore, given that deficits resulting from mTOR overactivity can be alleviated through treatment with rapamycin, it is possible that mTOR plays an important role in affecting cognitive functioning through synaptic plasticity. Further evidence for mTOR activity in neurodegeneration comes from recent findings demonstrating that eIF2α-P, an upstream target of the mTOR pathway, mediates cell death in prion diseases through sustained translational inhibition. Some evidence points to mTOR's role in reduced Aβ clearance as well. mTOR is a negative regulator of autophagy; therefore, hyperactivity in mTOR signaling should reduce Aβ clearance in the AD brain. Disruptions in autophagy may be a potential source of pathogenesis in protein misfolding diseases, including AD. Studies using mouse models of Huntington's disease demonstrate that treatment with rapamycin facilitates the clearance of huntingtin aggregates. Perhaps the same treatment may be useful in clearing Aβ deposits as well.
In the general census of 1884, the male population of the Don Cossacks was reported to number 425,000. The Don Cossacks were the largest of the ten cossack hosts then in existence, providing over a third of total cossack manpower available for military service.
Sources: en.wikipedia.org
It is the over-expression of efflux pump proteins observed in resistant cancer cells that allows them to produce these pumps in high quantities and/or increase their overall activity compared to normal, sensitive cells. A specific protein and member of the ATP-binding cassette (ABC) transporter family known as p-glycoprotein (P-gp), has been suggested to play a major role in the development of resistance in cancer cells by promoting drug efflux. Research on P-gp and other related efflux pumps is currently ongoing, but studies have suggested that they have the capacity to transport various types of chemotherapeutic agents out of cancer cells resulting in a significantly reduced bioavailability of such drugs, and ultimately failed chemotherapy treatments. The inhibition of efflux pumps has been suggested as a promising therapeutic target to overcome this mechanism of resistance in cancer cells, aiming to both restore chemotherapeutic drug bioavailability within the cells, yet avoid deregulating normal functioning pumps and reduce undesired adverse effects. Conversely, toxic drug interactions have posed a major obstacle to successfully developing efflux pump inhibitors and highlights the difficulty of targeted chemotherapeutic drug formulation. Many proteins involved in intracellular transport processes have been identified as fundamental contributors of resistance by impairing chemotherapeutic drug-target interactions.
=== Global helium spray === This method requires the part to be tested to be connected to a helium leak detector. The outer surface of the part to be tested will be located in some kind of a tent in which the helium concentration will be raised to 100% helium. If the part is small the vacuum system included in the leak testing instrument will be able to within a short amount of time reach low enough pressure (typically below 100mTorr) to allow for mass spectrometer operation. If the size of the part is too large, an additional vacuum pumping system may be required to reach low enough pressure in a reasonable length of time. Once operating pressure has been reached, the mass spectrometer can start its measuring operation. If leakage is encountered the small and "agile" molecules of helium will migrate through the cracks into the part. The vacuum system will carry any tracer gas molecule into the analyzer cell of the magnetic sector mass spectrometer. A signal will inform the operator of the value of the leakage encountered.
=== Generic names === Nicergoline is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and DCFTooltip Dénomination Commune Française.
21 May The WHO informs about the international 2022 monkeypox outbreak in non-endemic countries – an unprecedented number of cases detected outside of Africa after the first of these cases was detected on 6 May. On 24 May, the WHO states that the outbreak can be contained. The main method used for the early containment is 'ring vaccination' – vaccinating close contacts of positive cases via existing vaccines. 23 May Researchers report that CRISPR-Cas9 gene editing has been used to boost vitamin D in tomatoes. A study shows why decarbonization must be accompanied by strategies to reduce the levels of short-lived climate pollutants with near-term effects for climate goals. 24 May Scientists report the first 3D-printed lab-grown wood. It is unclear if it could ever be used on a commercial scale (e.g. with sufficient production efficiency and quality). A CDC study based on electronic health records shows that "one in five COVID-19 survivors aged 18–64 years and one in four survivors aged ≥65 years experienced at least one incident condition that might be attributable to previous COVID-19" or long COVID. On 18 May, an analysis of private healthcare claims shows that of 78,252 patients diagnosed with 'long COVID', 75.8% had not been hospitalized for COVID-19. 25 May – The world's smallest remote-controlled walking robot, measuring just half a millimetre wide, is demonstrated. Potential applications include the clearing of blocked arteries.
== Function == The protein encoded by this gene belongs to the family of G-protein coupled receptors that are preferentially activated by adenosine and uridine nucleotides. Two alternatively spliced transcript variants encoding the same protein isoform have been found for this gene.
Sources: en.wikipedia.org
He cut the spending proposal he sent to Congress to include funding for only the Space Shuttle, with perhaps an option to pursue the Earth orbital space station for the foreseeable future. AAP planners decided the Earth orbital workshop could be accomplished more efficiently by prefabricating it on the ground and launching it with a single Saturn V, which immediately eliminated Apollo 20. Budget cuts soon led NASA to cut Apollo 18 and 19 as well. Apollo 13 had to abort its lunar landing in April 1970 due to an in-flight spacecraft failure but returned its crew safely to Earth. The Apollo program made its final lunar landing in December 1972; the two unused Saturn Vs were used as outdoor visitor displays and allowed to deteriorate due to the effects of weathering. The USSR continued trying to develop its N1 rocket, after two more launch failures in 1971 and 1972, finally canceling it in May 1974, without achieving a single successful uncrewed test flight.
Islam dominates in Pakistan, with about 96.35% of the population being Muslim. Pakistan ranks second globally in Muslim population, and is home to 10.5% of the world's Muslims. Karachi is the largest Muslim city in the world. The majority follow Sunni Islam, with a significant presence of Sufism, while Shia Muslims constitute a minority. Shias represent between 5–25%. The Shia population in Pakistan was estimated at 42 million in 2019. As of 2012, 12% of Pakistani Muslims self-identify as non-denominational Muslims. The Ahmadis are a minority, officially considered non-Muslims. Ahmadis face persecution, banned from calling themselves Muslims since 1974.
== Contraindications == Nothing is known about the use of alfatradiol during pregnancy or lactation, or in patients under 18 years of age. The package leaflet recommends against using it under these circumstances.
=== United Kingdom === A Chick-fil-A operated in Edinburgh during the Spring of 2018. On October 10, 2019, Chick-fil-A returned to Europe, with the opening of a store at The Oracle shopping centre in Reading, UK. The store closed in March 2020 after The Oracle opted not to continue the lease of the location beyond the six-month pilot period in the face of continued protests over the chain's anti-LGBTQ stance. In February 2019, Chick-fil-A opened a store on a 12-month pilot scheme in Aviemore, Scotland. The store was closed in January 2020 amidst protests and controversy from locals and customers regarding the chain's former donations to charities supporting anti-LGBT rights causes. Chick-fil-A said that they had always planned a short-term stay at the location. Later, the company changed some policies, appointing its first head of diversity in 2020, and focused its charitable activities on education and hunger alleviation rather than opponents of same-sex marriage. In September 2023, the company planned to open five restaurants in the UK from early 2025, investing over $100M over the following ten years in the UK. The chain said that it would apply its charitable policies, including a $25,000 donation to a local organization on opening a Chick-fil-A restaurant and donation of surplus food to local charitable causes, to its UK branches too.
Sources: en.wikipedia.org
它属于合成修饰肽，同时激动 GIP 与 GLP-1 两种肠促胰素受体。这类分子通常被称为双重肠促胰素受体激动剂，与选择性 GLP-1 激动剂在靶点范围上不同。
分子上的脂肪酸侧链使其与血浆白蛋白结合增强，显著延长循环半衰期。半衰期延长后，稳定血药浓度可在较长的给药间隔内维持，因此常见用法为每周一次。
同时激活两条肠促胰素通路可能在胰岛素分泌、胃排空和食欲调节上产生叠加效应。与单靶点相比，临床研究中观察到的血糖与体重变化幅度通常更明显，但各通路的具体贡献比例尚无定论。
Liquid chromatography combined with mass spectrometry is the most common approach. Digestion followed by peptide mapping verifies the sequence and modification sites. Results are judged against a reference standard or a theoretically calculated mass.