deamidation comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-06-23. Numbers and descriptions here follow the published literature rather than marketing material.
Receptor activation produces downstream effects that differ by tissue. GLP-1 receptor signaling influences appetite regulation and insulin secretion in a glucose-dependent manner. GIP receptor activity contributes to metabolic handling of nutrients and may modulate adipose tissue. Glucagon receptor engagement raises energy expenditure and promotes hepatic lipid turnover, though the balance among these actions in humans is still being characterized. Preclinical models showed reductions in body weight and improved glycemic markers.
Clinical development has progressed through phase 2 trials in adults with obesity and type 2 diabetes, with phase 3 programs reported as ongoing. Reported outcomes include reductions in body weight and improvements in glycemic measures over defined treatment periods. Whether these effects translate into durable benefits after treatment ends remains an open question. Long-term safety data across broad populations are not yet complete, and regulatory decisions have not been announced.
多肽类化合物的表征通常依赖色谱与质谱联用技术。反相高效液相色谱用于评估纯度与有关物质，质谱用于确认分子量，肽图分析通过酶解碎片比对验证一级结构。这些手段组合使用，可以把目标产物与降解产物或类似物区分开来。单一方法往往不足以完成完整确认。
稳定性研究一般关注脱酰胺、氧化与聚集三类降解路径。脱酰胺多发生在天冬酰胺残基上，氧化常涉及甲硫氨酸与色氨酸，聚集则与浓度、温度以及容器界面接触有关。强制降解实验用于识别分子中较敏感的位点。这些结果会直接影响储存条件的设定与有效期的判断。
| Property | Value | Notes |
|---|---|---|
| Receptor targets | GIP, GLP-1, glucagon | One molecule activates all three pathways |
| Research identifier | LY3437943 | Code used in published trial reports |
| Development stage | Phase 3, reported as ongoing | Not approved by any regulatory agency |
| Route studied | Subcutaneous | Administration form used in clinical trials |
| Studied populations | Adults with obesity or type 2 diabetes | Enrollment criteria vary between trials |
Retatrutide is an investigational peptide developed by a pharmaceutical company as a multi-receptor agonist for treating obesity and type 2 diabetes. The compound emerged from research into gut-hormone analogues that act on several receptors simultaneously rather than on a single target. Early preclinical work examined how combined activity at three distinct receptors might produce greater metabolic effects than single-receptor compounds. Published phase 2 results have described substantial reductions in body weight among participants, although the compound remains unapproved in most jurisdictions as of the mid-2020s.
Pharmacologically, retatrutide acts as a triple agonist at the glucagon-like peptide-1 receptor, the glucose-dependent insulinotropic polypeptide receptor, and the glucagon receptor. Activation of the first two receptors is associated with improved insulin secretion and reduced appetite. The glucagon receptor component is thought to increase energy expenditure, a mechanism that distinguishes this molecule from dual-agonist compounds. Researchers continue to investigate how the three activities interact and whether the combined profile offers advantages that justify additional clinical testing.
Several questions about the compound remain unresolved. The durability of weight reduction after treatment stops, the frequency of gastrointestinal side effects, and the long-term cardiovascular profile are topics of ongoing study. Regulatory submissions and phase 3 trial outcomes have not been fully reported in the public literature. Because most available data come from controlled trials rather than general-population use, conclusions about effectiveness outside study settings are provisional. The distinction between established findings and open questions matters when interpreting early coverage of the drug.
Characterising a peptide of this size relies on a combination of chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the intact molecule from related impurities, while electrospray mass spectrometry confirms molecular mass and detects truncation or oxidation products. Peptide mapping after enzymatic digestion verifies the amino acid sequence and locates modified residues. Because the molecule carries a lipid chain, assays must also distinguish the correctly conjugated product from incompletely acylated species.
Peptides in this class degrade mainly through hydrolysis, oxidation, and aggregation. The lipid modification improves plasma residence time but can also promote self-association in aqueous solution at higher concentrations. Oxidation of methionine and deamidation of asparagine residues are common chemical liabilities that accumulate during storage. Stability studies therefore track purity loss, aggregate formation, and changes in receptor-binding potency over time under defined temperature and humidity conditions.
Pharmacologically the compound activates three receptors: GLP-1, GIP, and glucagon. GLP-1 and GIP signaling contribute to glucose-dependent insulin release, delayed gastric emptying, and reduced appetite, while glucagon receptor activation is associated with increased energy expenditure and hepatic fat oxidation. The single-molecule design is intended to keep these activities in one peptide rather than combining separate agents. Relative activity at each receptor differs, and the balance between them is a central question in interpretation. The glucagon component is partly offset by incretin-mediated insulin secretion, an interaction that remains incompletely characterized.
Development has progressed from single- and multiple-ascending-dose studies in healthy volunteers into larger randomized trials in adults with obesity, type 2 diabetes, and fatty liver disease. Early reports describe dose-dependent reductions in body weight and improvements in glycemic markers over treatment periods of several months. Whether the glucagon arm adds tolerability cost without added benefit is still debated. Long-term cardiovascular outcomes, effects after treatment stops, and performance in older or comorbid populations are open questions rather than settled findings. Approval status may change, so the current investigational label should be confirmed against regulatory sources.
== Applications == Cell biology utilizes tools that allow manipulation and visualization of proteins in living cells. An important example is the use of fluorescent proteins, such as the green fluorescent protein (GFP) or yellow fluorescent protein (YFP). Molecular biology methods allow these fluorescent proteins to be introduced and expressed in living cells as fusion proteins. However, the photo-physical properties of the fluorescent proteins are generally not suited for single-molecule spectroscopy. Fluorescent proteins have, in comparison to commercially available dyes, a much lower fluorescence quantum yield and are quickly destroyed upon excitation with a focused laser beam (photobleaching). The SNAP-tag® protein is an engineered version of the ubiquitous mammalian enzyme AGT, encoded in humans by the O-6-methylguanine-DNA methyltransferase (MGMT) gene. SNAP-tag was obtained using a directed evolution strategy, leading to a hAGT variant that accepts O6-benzylguanine derivatives instead of repairing alkylated guanine derivatives in damaged DNA. An orthogonal tag, called CLIP-tag™, was further engineered from SNAP-tag to accept O2-benzylcytosine derivatives as substrates, instead of O6-benzylguanine. Therefore, Clip-tag- and SNAP-tag-fused proteins can be labeled simultaneously in the same cells. A split-SNAP-tag version suitable for protein complementation assay and protein-protein interaction studies was later developed.
On the day of discovery, 19 February, alpha irradiation of the einsteinium target occurred in three three-hour sessions. The cyclotron was in the University of California campus, while the Radiation Laboratory was on the next hill. To deal with this situation, a complex procedure was used: Ghiorso took the catcher foils (there were three targets and three foils) from the cyclotron to Harvey, who would use aqua regia to dissolve it and pass it through an anion-exchange resin column to separate the transuranium elements from the gold and other products. The resultant drops entered a test tube, which Choppin and Ghiorso took in a car to get to the Radiation Laboratory as soon as possible. Thompson and Choppin used a cation-exchange resin column and the α-hydroxyisobutyric acid. The solution drops were collected on platinum disks and dried under heat lamps. The three disks were expected to contain, respectively, the fermium, no new elements, and the mendelevium. Finally, they were placed in their own counters, which were connected to recorders such that spontaneous fission events would be recorded as huge deflections in a graph showing the number and time of the decays. There thus was no direct detection, but by observation of spontaneous fission events arising from its electron-capture daughter 256Fm. The first one was identified with a "hooray" followed by a "double hooray" and a "triple hooray". The fourth one eventually officially proved the chemical identification of the 101st element, mendelevium. In total, five decays were reported up until 4 a.m.
Professor Richard Hilary Templer. Lately Director of Innovation, Grantham Institute, Imperial College London. For services to Climate Innovation. Dr. Gillian Romaine Tett. Editorial Board, Financial Times. For services to Economic Journalism. Usha Ladwa-Thomas. Race Adviser, Welsh Government. For services to Black, Asian and Minority Ethnic Communities. Margaret Ann Throup, MP. Member of Parliament for Erewash. For Political and Public Service. Jane Elizabeth Toogood. Co-Chair, Hydrogen Delivery Council. For services to the Low Carbon Hydrogen Sector. Sara Louise Tough. Executive Director, Children's Services, Norfolk County Council. For services to Education and Children's Social Care. John Henry Trayner. Lately Managing Director, Go-Ahead London. For services to Transport, to Skills and to Education in London. Marcus Edward Trescothick. Mental Health Ambassador, Professional Cricketers' Association. For services to Mental Ill Health. Professor Joyce Ann Tyldesley. Professor of Egyptology, University of Manchester. For services to Egyptology and Heritage. Nicola Madeline van der Drift. Chief Executive, International Bomber Command Centre. For services to Heritage. Louise van der Straeten. Senior Lawyer, Serious Fraud Office. For services to the Administration of Justice. Vinaichandra Guduguntla Venkatesham. Chief Executive Officer, Arsenal Football Club. For services to Sport. Ewan Andrew Venters. Chief Executive, Hauser & Wirth and Chair, GREAT Private Sector Council. For services to International Trade. Robert Iain Wainwright. Founder, Doddie Aid.
Sources: en.wikipedia.org
== Formation == Brine pockets and channels are formed as seawater freezes, through a process called brine rejection. When sea ice forms, the water molecules form ice crystals, which have a regular lattice structure. The larger salt (NaCl) molecules in the sea water cannot be incorporated into this lattice, resulting in the salt being rejected from the sea ice. As seawater freezes and more pure water ice forms, the salt becomes more highly concentrated in the remaining sea water, forming a brine. As the brine salinity increases it becomes more dense compared to the surrounding sea ice, and the brine sinks downward through the ice, forming brine pockets. As the brine pockets form, they begin to coalesce, forming pockets of dense and saline brine. As these larger pockets of brine become interconnected, the may form a network of brine channels within the ice.
=== United Kingdom === GDK's first store in the United Kingdom, was opened on 6 July 2015, on Bull Street in Birmingham, England. In May 2019, it was estimated that the chain served £1 million worth of kebabs in its restaurants in the UK every week. GDK also announced their plan to open a new restaurant every two weeks for the remainder of 2019 as part of a "relentless UK growth" plan. In September 2019, GDK's Fulham Broadway site was classed as London's number one place to eat on Tripadvisor. In October 2020, it had 47 restaurants, with hopes by the company to open a further 12 by the end of 2020. In December 2020, its Peterborough new restaurant marked its 50th UK restaurant. In February 2021, the chain announced its plan to open 47 restaurants by the end of 2021 in the UK. It opened 39 new restaurants in the UK in 2021, adding to their pre-existing 52 restaurants at the start of 2021. In February 2022, the company announced its plan to open 78 more restaurants in the UK in 2022, bringing their total to 170 restaurants in the UK. Adding 2,900 workers to their 3,500 workforce at the time in the UK. The chain opened their 100th UK restaurant at their Covent Garden, London site on 10 May 2022. In June 2022, Atul Pathak, former owner of the largest McDonald's franchise in the UK of 43 restaurants, announced a partnership with GDK, with 30 planned sites to be set up in the UK as part of the deal. In January 2025, German Doner Kebab (GDK) opened its first London train station location at Victoria Station, marking its 144th UK outlet and 55th in the capital.
John Kenneth Stille subsequently reported the coupling of a variety of alkyl tin reagents in 1978 with numerous aryl and acyl halides under mild reaction conditions with much better yields (76%–99%). Stille continued his work in the 1980s on the synthesis of a multitude of ketones using this broad and mild process and elucidated a mechanism for this transformation.
Sources: en.wikipedia.org
=== Strontium === The addition of lime to soils which are poor in calcium can reduce the uptake of strontium by plants. Likewise in areas where the soil is low in potassium, the addition of a potassium fertilizer can discourage the uptake of cesium into plants. However such treatments with either lime or potash should not be undertaken lightly as they can alter the soil chemistry greatly, so resulting in a change in the plant ecology of the land.
Another interesting scaffold used as a platform for supramolecularly assembled ArMs are multidrug resistance regulators (MDRs), particularly a PadR family of proteins without native catalytic activity, whose function in nature is the recognition of foreign agents and to activate subsequent cellular response. Among them, Lactococcal multidrug resistance regulator (LmrR) was mainly used to create ArMs, using different strategies, including the supramolecular one. Namely, Roelfes et al. incorporated Cu(II) phenanthroline complex in the hydrophobic pocket of LmrR and performed Friedel-Crafts reaction enantioselectively; and Fe heme complex which catalyzed cyclopropanation enantioselectively.
The IFP was the third-largest party until it was unseated by the EFF and is one of the few parties to have consecutive representation in parliament since democracy in 1994. The IFP apart from the ANC was part of the National Government for 10 years. The IFP champions the rights of traditional leaders and advocates for policies which favour free markets. The party is opposed to socialism and communist policies. Because the ANC had such a large majority in parliament, smaller parties are constantly forming alliances and coalitions in order to act as a stronger opposition to the ANC-run legislative and executive branches. In the 2024 South African general election, support for the ruling African National Congress (ANC) significantly declined; the ANC remained the largest party but lost the parliamentary majority that it had held since the inaugural post-apartheid election in 1994. The centrist Democratic Alliance (DA) remained in second place with a slight increase. uMkhonto we Sizwe (MK) A left-wing populist party founded 6 months prior to the 2024 election and led by former president Jacob Zuma came in third place. Most of the ANC's loss of support flowed into the MK, while the DA saw some gains, and the EFF lost some support (and its status as the third-largest party in parliament).
Sources: en.wikipedia.org
It is a synthetic peptide triagonist that engages GIP, GLP-1, and glucagon receptors. Investigational compounds in this class are studied for metabolic conditions rather than for a single organ system.
No regulatory agency has approved it for any indication. It remains an investigational product studied within controlled clinical trial programs.
A dual agonist engages two receptor targets, typically GIP and GLP-1. A triagonist adds glucagon receptor activity, which is intended to influence energy expenditure alongside appetite and glucose handling.
常用质谱测定分子量，再结合肽图或序列分析验证一级结构。单一检测手段一般难以排除结构相近的类似物。多种方法相互印证更为可靠。