The short version of peptide backbone fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-15. Anything still debated is marked as such rather than presented as settled.
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C225H348N48O68 | Peptide backbone with a fatty diacid chain |
| Molecular weight | About 4813 Da | Calculated from the formula |
| Receptor targets | GIP and GLP-1 receptors | Dual agonist activity at both sites |
| Route of administration | Subcutaneous injection | No approved oral form at present |
| Elimination half-life | About 5 days | Supports extended intervals between administrations |
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.
Development of tirzepatide took place under a research program that sought to test whether simultaneous engagement of two incretin receptors would produce greater metabolic effects than single-receptor agonism. Clinical trials were organized into the SURPASS series for type 2 diabetes and the SURMOUNT series for obesity and weight management. Regulatory clearance for type 2 diabetes came in 2022 in the United States, followed by approval for chronic weight management in 2023. The trial programs reported reductions in glycated hemoglobin and body weight relative to comparators, though long-term cardiovascular and durability data continue to accumulate.
Storage recommendations for tirzepatide generally specify refrigeration at 2–8 °C to maintain stability. The peptide should be protected from light and kept in its original packaging to prevent aggregation or adsorption. Freezing is not recommended because freeze-thaw cycles can cause aggregation or precipitation. Once dispensed, storage conditions and in-use periods follow product-specific labeling, which may allow room temperature storage for a limited time.
Degradation pathways for tirzepatide include deamidation, oxidation, and aggregation, which are common for therapeutic peptides. These processes can be monitored by size-exclusion chromatography (SEC) for aggregates and ion-exchange chromatography for charge variants. Forced degradation studies under acidic, basic, oxidative, and thermal stress help identify potential impurities. The exact stability profile depends on formulation, concentration, and container-closure system.
Analytical characterization of tirzepatide typically employs reversed-phase high-performance liquid chromatography (RP-HPLC) for purity assessment and peptide mapping. Mass spectrometry, often coupled with electrospray ionization, confirms molecular weight and sequence integrity. Amino acid analysis and capillary electrophoresis may also be used to detect impurities or degradation products. These methods are essential for batch release and stability studies.
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。
质量控制环节关注外观、含量、纯度、有关物质、水分与微生物限度等项目。检测结果需要有对照品和系统适用性数据支持，单次测定不足以判定批次的稳定性。实验室之间方法转移时，色谱柱品牌与梯度差异常导致保留时间漂移，因此方法验证十分必要。
Lyophilized material is generally held at -20 degrees Celsius or lower, desiccated and protected from light, where it remains stable for extended periods. Reconstituted or ready-to-use solution is usually kept at 2 to 8 degrees Celsius with minimal agitation. Repeated freeze-thaw cycles should be avoided because they promote aggregation and reduce the soluble monomer fraction. Shipment of frozen solid commonly uses dry ice, while refrigerated liquid moves with validated cold packs. Stability beyond documented periods is not established.
Characterization of the peptide relies on reversed-phase high-performance liquid chromatography for purity and related-substance profiling, with ultraviolet detection near 214 nanometers. Mass spectrometry confirms molecular mass and reveals modifications such as oxidation or deamidation. Peptide mapping after enzymatic digestion verifies the amino acid sequence, while amino acid analysis supplies compositional data. Circular dichroism and infrared spectroscopy are used to assess secondary structure, particularly the alpha-helical content that influences aggregation behavior in solution.
== Autoproteolytic activity == The use of high-resolution ion-mobility mass spectrometry (IMS-MS) on HPLC-purified alpha-synuclein in vitro has shown alpha-synuclein to be autoproteolytic (self-proteolytic), generating a variety of small molecular weight fragments upon incubation. The 14.46 kDa protein was found to generate numerous smaller fragments, including 12.16 kDa (amino acids 14–133) and 10.44 kDa (40–140) fragments formed through C- and N-terminal truncation and a 7.27 kDa C-terminal fragment (72–140). The 7.27 kDa fragment, which contains the majority of the NAC region, aggregated considerably faster than full-length alpha-synuclein. It is possible that these autoproteolytic products play a role as intermediates or cofactors in the aggregation of alpha-synuclein in vivo.
David Hasselhoff as S.H.I.E.L.D. Agent Colonel Nick Fury Lisa Rinna as S.H.I.E.L.D. Agent Contessa Valentina "Val" Allegra De Fontaine Sandra Hess as Andrea Von Strucker/Viper Neil Roberts as S.H.I.E.L.D. Agent Alexander Pierce Garry Chalk as S.H.I.E.L.D. Agent Timothy Aloysius "Dum-Dum" Dugan Tracy Waterhouse as S.H.I.E.L.D. Agent Kate Neville Tom McBeath as S.H.I.E.L.D. Director General Jack Pincer Ron Canada as S.H.I.E.L.D. Agent Gabriel Jones Adrian G. Griffiths as S.H.I.E.L.D. Agent Clay Quartermain Peter Haworth as Dr. Arnim Zola Campbell Lane as Baron Wolfgang Von Strucker Scott Heindl as Werner Von Strucker Mina E. Mina as H.Y.D.R.A. Cairo Lieutenant Stellina Rusich as Inspector Gail Runciter Rick Ravanello as S.H.I.E.L.D. Agent J. Vaughn Roger Cross as S.H.I.E.L.D. Agent #1 Bill Croft as H.Y.D.R.A. Agent Garotte Terry David Mulligan as U.S. President
=== Ammonia solutions === The alkali metals dissolve slowly in liquid ammonia, forming ammoniacal solutions of solvated metal cation M+ and solvated electron e−, which react to form hydrogen gas and the alkali metal amide (MNH2, where M represents an alkali metal): this was first noted by Humphry Davy in 1809 and rediscovered by W. Weyl in 1864. The process may be speeded up by a catalyst. Similar solutions are formed by the heavy divalent alkaline earth metals calcium, strontium, barium, as well as the divalent lanthanides, europium and ytterbium. The amide salt is quite insoluble and readily precipitates out of solution, leaving intensely coloured ammonia solutions of the alkali metals. In 1907, Charles A. Kraus identified the colour as being due to the presence of solvated electrons, which contribute to the high electrical conductivity of these solutions. At low concentrations (below 3 M), the solution is dark blue and has ten times the conductivity of aqueous sodium chloride; at higher concentrations (above 3 M), the solution is copper-coloured and has approximately the conductivity of liquid metals like mercury. In addition to the alkali metal amide salt and solvated electrons, such ammonia solutions also contain the alkali metal cation (M+), the neutral alkali metal atom (M), diatomic alkali metal molecules (M2) and alkali metal anions (M−). These are unstable and eventually become the more thermodynamically stable alkali metal amide and hydrogen gas. Solvated electrons are powerful reducing agents and are often used in chemical synthesis.
Absinthe has been frequently described in modern times as being hallucinogenic, a claim refuted by modern science. The belief that absinthe induces hallucinogenic effects is rooted, at least partly, in the findings of 19th-century French psychiatrist Valentin Magnan, who carried out ten years of experiments with wormwood oil. In the course of this research, he studied 250 cases of alcoholism and concluded that those who abused absinthe were worse off than those who abused other alcoholic drinks, experiencing rapid-onset hallucinations. Such accounts by opponents of absinthe (like Magnan) were cheerfully embraced by famous absinthe drinkers, many of whom were bohemian artists or writers. Two famous artists who helped popularise the notion that absinthe had powerful psychoactive properties were Toulouse-Lautrec and Vincent van Gogh. In one of the best-known written accounts of absinthe drinking, an inebriated Oscar Wilde described a phantom sensation of having tulips brush against his legs after leaving a bar at closing time. Notions of absinthe's alleged hallucinogenic properties were again fuelled in the 1970s when a scientific paper suggested that thujone's structural similarity to tetrahydrocannabinol (THC), the active chemical in cannabis, presented the possibility of THC receptor affinity. Counterevidence to this was published in 1999. The debate over whether absinthe produces effects on the human mind in addition to those of alcohol has not been resolved conclusively. The effects of absinthe have been described by some as mind-opening.
Amylin, or islet amyloid polypeptide (IAPP), is a 37-residue peptide hormone. It is co-secreted with insulin from the pancreatic β-cells in the ratio of approximately 100:1 (insulin:amylin). Amylin plays a role in glycemic regulation by slowing gastric emptying and promoting satiety, thereby preventing spikes in blood glucose levels after a meal. IAPP is processed from an 89-residue coding sequence. Proislet amyloid polypeptide (proIAPP, proamylin, proislet protein) is produced in the pancreatic beta cells (β-cells) as a 67 amino acid, 7404 Dalton pro-peptide and undergoes post-translational modifications including protease cleavage to produce amylin.
Sources: en.wikipedia.org
=== Illegal gambling groups === Jogo do bicho (Animal game) is an illegal gambling game in Brazil, which is still incredibly popular and sought out despite its federal prohibition in 1946. The game is played all around the country, with lottery-style drawings in every state occurring daily in its headquarters in Greater Rio de Janeiro. The game is controlled by bosses, called bicheiros or banqueiros ("bankers"). Jogo do Bicho is a longstanding staple in Brazilian culture, with thousands participating in the game daily. Because of its potential to circulate and raise large sums of money, control of Jogo do Bicho is lucrative and largely contributes to corruption, with politicians, judicial personnel, and members of the police force all monetarily and politically benefitting from it. Bicheiros also contribute funding to social programs, such as samba schools, which play a critical role in cultural festivities such as Brazilian Carnival. Because of this, Jogo do Bicho, and in turn its bicheiros, are deeply ingrained in Brazilian culture, especially in Rio de Janeiro, and contribute to the landscape of organized crime and corruption.
Blackledge-Gair House (at 111 Madison Avenue; added January 9, 1983) Demarest-Atwood House (at 84 Jefferson Avenue; added July 24, 1984) Peter Huyler House (50 County Road; added January 9, 1983) Benjamin P. Westervelt House (at 235 County Road; added January 9, 1983)
Oxymorphone, sold under the brand names Numorphan and Opana among others, is a highly potent opioid analgesic indicated for treatment of severe pain. Pain relief after injection begins after about 5–10 minutes; after oral administration it begins after about 30 minutes and lasts about 3–4 hours for immediate-release tablets and 12 hours for extended-release tablets. The elimination half-life of oxymorphone is much faster intravenously, and as such, the drug is most commonly used orally. Like oxycodone, which metabolizes to oxymorphone, oxymorphone has a high abuse potential. Oxymorphone was developed in Germany in 1914. It was patented in 1955 and approved for medical use in 1959. In June 2017 the FDA asked Endo Pharmaceuticals to remove its product from the US market. This was in part due to the opioid epidemic in the US, and the fact that a 2012 reformulation failed to stop illicit injection of the drug. Endo responded by voluntarily removing Opana ER from the market a month later. Generic versions of extended-release oxymorphone, such as those manufactured by Amneal Pharmaceuticals, are still available in the US.
HIV infection In October 2016, scientists from Emory University and National Institute of Allergy and Infectious Diseases (NIAID) published a paper which claimed that they applied daily ART (antiretroviral therapy) of 90 days followed by simianized (rhesus macaques) anti α4β7 antibody on SIV+ rhesus macaques for 23 weeks. Twenty three months after stopping both ART and anti-α4β7 antibody treatment, the in vivo SIV level still remained undetectable. Therefore, treating HIV+ people with ART and anti-α4β7 simultaneously may be a new therapy that could potentially lead to an HIV infection cure. In mice, vedolizumab was not able to prevent or control HIV-infections. Phase 1 clinical trial of that therapy has been initialized by NIAID since May 2016. For each of the participants, they will get vedolizumab infusions every four weeks for 30 weeks. Before the 23rd week of vedolizumab infusions, cART (combination ART) is kept. During the 30 weeks, blood draws are repeated for baseline tests. After the 22-week-cART is stopped, both viral load and CD4 count will be monitored biweekly. If HIV viral load goes high or their CD4 cell counts decrease by too much when vedolizumab is used alone, cART will be brought back on the participants. The published results from this clinical trial suggest "that blockade of α4β7 may not be an effective strategy for inducing virological remission in HIV-infected individuals after ART interruption" because only one patient showed prolonged virus suppression.
== Chemical properties == The cyclic thiourea derivative thiamazole is a white to matte brown crystalline powder with a characteristic odour. The boiling point is 280 °C (decomposition). Thiamazole is soluble in water, ethanol and chloroform, but hardly soluble in ether. Thiamazole acts as a free radical scavenger for radicals such as the hydroxyl radical (•OH) radical. It is used as free radical scavenger in organic chemistry.
Sources: en.wikipedia.org
=== Late modern botany === Building upon the gene-chromosome theory of heredity that originated with Gregor Mendel (1822–1884), August Weismann (1834–1914) proved that inheritance only takes place through gametes. No other cells can pass on inherited characters. The work of Katherine Esau (1898–1997) on plant anatomy is still a major foundation of modern botany. Her books Plant Anatomy and Anatomy of Seed Plants have been key plant structural biology texts for more than half a century.
The eyes are posed using an eye cap that keeps them shut and in the proper expression. The mouth may be closed via suturing with a needle and ligature, using an adhesive, or by setting a wire into the maxilla and mandible with a needle injector, a specialized device most commonly used in North America and unique to mortuary practice. Care is taken to make the expression look as relaxed and natural as possible, and ideally, a recent photograph of the deceased in good health is used as a reference. The process of closing the mouth and eyes, shaving, etc. is collectively known as setting the features. Features may also be set after the completion of the arterial embalming process, which allows the embalmer to clean and remove any purge that occurs during the embalming process.
==== Types of diabetes mellitus ==== Between 1850 and 1875, French researchers Apollinaire Bouchardat and E. Lancereux acknowledged a need for classification. They distinguished between those diabetics that were lean, had severe symptoms, poor outcomes, and pancreatic lesions at autopsy (diabetes maigre), and those that were overweight, presented later in life with a milder form of the disease and had a better prognosis if put on a low-calorie diet (diabetes gras). These descriptions are comparable to the two types identified by Ayurvedic physicians Sushruta and Charaka (400–500 AD), with one type being associated with youth and the other with being overweight. Harold Percival Himsworth established a clearer distinction in 1936, differentiating two types of diabetes based on sensitivity to insulin (both injected and pancreatic). In 1950, R. D. Lawrence observed that some diabetics were deficient in insulin and that some were not. Philip Hugh-Jones, while working in Jamaica in 1955, clarified Lawrence's classification and coined the terms "type 1" and "type 2" diabetes. He also noted a rarer variety observed in insulin-resistant youth (whose condition could not be placed into the two types). He called this third group "type J", where J stood for Jamaica. The terms type 1 and 2 were for some time forgotten. In 1976, they were revived and popularized by Andrew Cudworth after he discovered the link between type 1 diabetes and a specific genetic marker.
== Actin remodeling cycle == Cell surface (cortical) actin remodeling is a cyclic (9-step) process where each step is directly responsive to a cell signaling mechanism. Over the course of the cycle, actin begins as a monomer, elongates into a polymer with the help of attached actin-binding-proteins, and disassembles back into a monomer so the remodeling cycle may commence again. The dynamic function of actin remodeling is directly correlated to the immense variability of cell shape, structure, and behavior.
Sources: en.wikipedia.org
It is a synthetic 39-amino-acid peptide that acts on two incretin receptors, the GIP receptor and the GLP-1 receptor. It is given by subcutaneous injection and has a circulating half-life of roughly five days. It is not a small molecule and is not absorbed usefully from the gut in conventional oral form.
Selective agents act on one receptor, while tirzepatide engages both GIP and GLP-1 receptors. The added GIP activity may contribute effects on insulin sensitivity and on fat metabolism. Whether the dual action produces meaningful clinical advantages beyond differences in potency is still being examined.
The downstream consequences of GIP receptor activation are not fully characterised in humans. It is also unclear how much each receptor contributes to appetite reduction and to shifts in body composition. Published work describes associations and proposed pathways rather than settled causal chains.
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.