A practical reference on peptide backbone: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-29 and is reviewed periodically as new material appears.
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.
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.
| 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 |
溶解操作一般使用注射用水或适宜的水性缓冲液，必要时加入少量助溶剂以改善溶解速度，但应避免剧烈涡旋振荡，因为剪切力可能促进聚集。配制后的溶液在冷藏条件下的稳定时间通常短于固体形态，具体时限取决于浓度、缓冲体系与容器材质。是否加入防腐成分，则取决于用途是否为多次取样。
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。
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.
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.
After subcutaneous injection, absorption is gradual, and peak plasma levels are generally reached within one to three days. Albumin binding extends the apparent half-life to roughly five days, which supports a weekly administration schedule. Metabolism proceeds mainly through proteolytic cleavage of the peptide backbone and beta-oxidation of the fatty acid chain, rather than through cytochrome P450 pathways. Eliminated fragments are largely recycled through general protein turnover, and excretion of intact drug in urine is minimal. These properties distinguish the molecule from short-acting incretin mimetics.
Tirzepatide is a synthetic peptide of 39 amino acids engineered from the native glucose-dependent insulinotropic polypeptide sequence. Its structure incorporates several non-natural residues and a C-terminal segment derived from glucagon-like peptide-1, together with a C20 fatty diacid moiety attached through a linker. The lipophilic side chain promotes binding to serum albumin, which slows renal clearance after administration. The compound is classified as a dual incretin receptor agonist and is supplied as a lyophilized powder for reconstitution or as a preformulated solution, depending on the presentation.
The peptide activates two G protein-coupled receptors, GIPR and GLP-1R. Binding triggers adenylyl cyclase activity and raises intracellular cyclic AMP in pancreatic beta cells, which potentiates insulin release when glucose is elevated. Signaling in the central nervous system is associated with reduced appetite and lower energy intake, while effects on gastric emptying and glucagon secretion are also reported. Because activity at both receptors is retained, the pharmacological profile is often described as incretin-based rather than selective for a single receptor.
The climate of mainland Portugal and Madeira, together with their surrounding waters, is Mediterranean, whereas the Azores and its adjacent waters mainly have a temperate oceanic climate. Portugal's terrain has a diverse variety of regional climates for its size. The average temperature in Portugal varies from 4–20 °C (39.2–68.0 °F) in the mainland, around 18 °C (64.4 °F) in the Azores, and 9–19 °C (48.2–66.2 °F) in Madeira. The Iberian Peninsula is located at the southern margin of the temperate zone and at the northern margin of the subtropical high-pressure zone. Additionally, Portugal's climate is influenced by the seasonal latitudinal shift of the jet stream, which directly impacts the trajectory of the polar front. Typically in the winter, the jet stream moves southwards and Portugal comes under the influence of the polar front, producing colder temperatures. When the polar front moves northward, Portugal comes under the influence of the Azores High bringing atmospheric stability during the summer. Upwelling occurs at the coast creating the Nortada, a summer wind along the coast. Wildfires are a serious challenge in Portugal, with nearly 30% of those recorded in 2024 having an undetermined origin and arson accounting for almost five-sixths of the total burned area. Between 2014 and 2024, Portugal recorded an annual average of 12,496 fires and 112,455 ha (434 sq mi) burned, making it the European Union country with both the highest average number of wildfires and the greatest average burned area over that period.
=== Combination hemoglobinopathies === A combination hemoglobinopathy occurs when someone inherits two different abnormal hemoglobin genes. Alpha thalassemia can coexist with other hemoglobinopathies such as sickle cell disease and beta thalassemia. When alpha thalassemia carrier or trait combines with another hemoglobinopathy, the symptoms are generally those of the other condition.
double-stranded DNA (dsDNA) Any DNA molecule that is composed of two antiparallel, complementary deoxyribonucleotide polymers, known as strands, which are bonded together by hydrogen bonds between the complementary nucleobases. Though it is possible for DNA to exist as a single strand, it is generally more stable and more common in double-stranded form. In most cases, the complementary base pairing causes the twin strands to coil around each other in the shape of a double helix.
Amino acid-based formula is a type of infant milk formula made from individual amino acids. It is hypoallergenic and intended for infants suffering from severe allergy to milk and various gastrointestinal conditions, such as food protein-induced enterocolitis syndrome and malabsorption syndromes. It is sometimes referred to as elemental formula but this is considered a misleading name. Issues with the use of amino acid-based formula include its high cost and its unpalatable taste. Intake of amino-acid formula for healthy infants shows no advantage in growth.
Although for the rest of his career Heseltine's role in Thatcher's downfall earned him enmity from Thatcher's supporters in the Conservative party, this opprobrium was not universal. In a reference to the reluctance of the Cabinet to support Thatcher on the second ballot, Edward Leigh said of Heseltine: "At least he stabbed her in the front". Heseltine believed that he would have defeated Thatcher if she had contested the second ballot. It has been suggested that he should have withdrawn after weakening her on the first ballot, and that he would have been restored to the Cabinet whether or not she continued as prime minister; he writes that this was never seriously suggested at the time.
Sources: en.wikipedia.org
=== Molecular self-assembly === Molecular self-assembly is the construction of systems without guidance or management from an outside source (other than to provide a suitable environment). The molecules are directed to assemble through non-covalent interactions. Self-assembly may be subdivided into intermolecular self-assembly (to form a supramolecular assembly), and intramolecular self-assembly (or folding as demonstrated by foldamers and polypeptides). Molecular self-assembly also allows the construction of larger structures such as micelles, membranes, vesicles, liquid crystals, and is important to crystal engineering.
Ned Lagin (born March 17, 1948) is an American artist, photographer, scientist, composer, and keyboardist. Lagin is considered a pioneer in the development and use of minicomputers and personal computers in real-time stage and studio music composition and performance. He is known for his electronic music composition Seastones, for performing with the Grateful Dead, and for his photography and art.
Hackenberger's research at the Leibniz Research Institute focuses on chemical strategies to functionalize proteins and antibodies using highly selective chemical reactions to generate protein-based therapeutics against cancer, Alzheimer's and viral infections. A particular focus of Hackenberger's research group is the engineering of new reactions for the modification and cellular delivery of proteins and antibodies to advance their use in biological and pharmacological research.
=== Medications === Prolactin secretion in the pituitary lactotroph cells is normally suppressed by the brain chemical dopamine, which binds to dopamine receptors. Drugs that block the effects of dopamine at the pituitary or deplete dopamine stores in the brain may cause the pituitary to secrete excess prolactin without an inhibitory effect. These drugs include the typical antipsychotics: phenothiazines such as chlorpromazine, and butyrophenones such as haloperidol; atypical antipsychotics such as risperidone and paliperidone; gastroprokinetic drugs used to treat gastro-esophageal reflux and medication-induced nausea (such as that from chemotherapy): metoclopramide and domperidone; less often, alpha-methyldopa and reserpine, used to control hypertension; and TRH. Aripiprazole, while an atypical antipsychotic, lowers prolactin levels as it is contains both agonistic and antagonistic dopamine-receptor activity. It is well known that estrogen stimulates prolactin secretion by upregulating the formation of lactotrophs. However, there is mixed evidence on whether estrogen-containing oral contraceptives significantly increase prolactin levels. Gender-affirming therapy for transgender women that includes estrogen and antiandrogens has been shown to increase prolactin levels, but it is unclear whether the cause is due to the estrogen or antiandrogen therapy. The melatonin receptor agonist ramelteon also increases the risk of hyperprolactinemia, however, the mechanism is unclear.
WOSM's bureau is its secretariat, which carries out the instructions of its conference and committee. The bureau is administered by the secretary general, supported by a staff of technical resource personnel. A bureau was established in London, England in 1922, moved to Ottawa, Ontario, Canada in 1959, Geneva, Switzerland after 1 May 1968 and Kuala Lumpur after August 2013.
Sources: en.wikipedia.org
Other means of fortifying foods via genetic engineering have been explored. Research on rice began in 1982. The first field trials of golden rice cultivars were conducted in 2004. The result was "Golden Rice", a variety of Oryza sativa rice produced through genetic engineering to biosynthesize β-carotene, a precursor of retinol, in the edible parts of rice. In May 2018, regulatory agencies in the United States, Canada, Australia and New Zealand had concluded that Golden Rice met food safety standards. In July 2021, the Philippines became the first country to officially issue the biosafety permit for commercially propagating Golden Rice. However, in April 2023, the Supreme Court of the Philippines issued a Writ of Kalikasan ordering the Department of Agriculture to stop the commercial distribution of genetically modified rice in the country.
At the Congress of Erfurt (September–October 1808), France and Russia further agreed on the division of Sweden into two parts separated by the Gulf of Bothnia, where the eastern part became the Russian Grand Duchy of Finland. British voluntary attempts to assist Sweden with humanitarian aid remained limited, and did not prevent Sweden from adopting a more Napoleon-friendly policy. The war between Denmark and Britain effectively finished with a British victory at the Battle of Lyngør in 1812, involving the destruction of the last large Dano–Norwegian ship—the frigate Najaden.
== Structure == Glutathione reductase from human erythrocytes is a homodimer consisting of 52kDa monomers, each containing 3 domains. GR exhibits single sheet, double layered topology where an anti-parallel beta-sheet is largely exposed to the solvent on one face while being covered by random coils on the other face. This includes and NADPH-binding Domain, FAD-binding domain(s) and a dimerization domain. Each monomer contains 478 residues and one FAD molecule. GR is a thermostable protein, retaining function up to 65 °C.
==== MeSH E05.196.630 – microchip analytical procedures ==== MeSH E05.196.630.465 – microfluidic analytical techniques MeSH E05.196.630.465.340 – electrophoresis, microchip MeSH E05.196.630.570 – microarray analysis MeSH E05.196.630.570.660 – oligonucleotide array sequence analysis MeSH E05.196.630.570.700 – protein array analysis MeSH E05.196.630.570.850 – tissue array analysis
A number of former Wildcats have gone on to pursue successful professional NBA careers (especially during the Lute Olson era), including Gilbert Arenas, Richard Jefferson, Mike Bibby, Jason Terry, Sean Elliott, Damon Stoudamire, Khalid Reeves, Luke Walton, Hassan Adams, Salim Stoudamire, Andre Iguodala, Channing Frye, Brian Williams (later known as Bison Dele), Sean Rooks, Jud Buechler, Michael Dickerson, Chase Budinger, Jordan Hill, Jerryd Bayless, Derrick Williams, Kadeem Allen, Aaron Gordon, Solomon Hill, Rondae Hollis-Jefferson, Stanley Johnson, T.J McConnell, Lauri Elias Markkanen, Kobi Simmons, Steve Kerr, Deandre Ayton, Rawle Alkins, and Allonzo Trier. Kenny Lofton, now best known as a former Major League Baseball star, was a four-year letter winner as a Wildcat basketball player (and was on the 1988 Final Four team), before one year on the Arizona baseball team. Another notable former Wildcat basketball player is Eugene Edgerson, who played on the 1997 and 2001 Final Four squads, and spent some of his professional careers as one of the Harlem Globetrotters as "Wildkat" Edgerson.
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 binds and activates both the GIP and GLP-1 receptors, making it a dual incretin receptor agonist. Single-receptor GLP-1 agonists act on one target only. The dual profile is the defining pharmacological feature of the molecule.