deamidation is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
固体状态的 tirzepatide 通常以冻干粉形式保存,推荐在低温、避光、干燥条件下存放,常见区间为 2 至 8 摄氏度,长期保存可考虑更低温度并避免反复冻融。冻融循环会导致肽链聚集或析出,从而影响后续定量结果。容器密封性与湿度控制同样是稳定性研究中反复强调的因素。
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.
| 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 |
Like most synthetic peptides of this size, the material is commonly supplied as a lyophilised powder that appears white to off-white. It dissolves in aqueous buffers and in mixtures of water with a small proportion of organic solvent, though the fatty acid portion reduces solubility in pure water relative to short peptides. Hygroscopic behaviour is reported for many peptide powders, so weighing is usually performed quickly and under controlled humidity. Working solutions are typically prepared fresh and kept cold.
Long-term storage of lyophilised peptide powder is generally at minus twenty degrees Celsius or colder, with desiccant and protection from light. Short-term storage at two to eight degrees Celsius is common during active use. In solution, stability depends strongly on pH, concentration, and the presence of preservatives, and hydrolysis or aggregation can develop over weeks. Published stability data specific to this molecule are limited, so recommended conditions for research material are usually extrapolated from general peptide handling practice rather than from a dedicated study.
Bulk peptide material is normally characterised by reversed-phase high-performance liquid chromatography, which separates the target sequence from truncation products and other closely related impurities. Ultraviolet detection near 214 nanometres is common because the peptide backbone absorbs in that region. Mass spectrometry, usually electrospray ionisation coupled to a mass analyser, is used to confirm the molecular mass. Because the molecule carries a lipophilic side chain, gradient methods often need a relatively high organic modifier fraction to elute it within a practical retention window.
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.
Tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor, making it a dual agonist rather than a selective agent. Engagement of the GLP-1 receptor is linked to glucose-dependent insulin release, slower gastric emptying, and reduced appetite signalling. The relative contribution of the GIP arm remains an active research question; proposed roles include improved insulin sensitivity and altered adipose tissue handling. Receptor occupancy studies suggest the molecule interacts with both targets at circulating concentrations achieved during therapy.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Identity and purity of tirzepatide are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Because the molecule carries several modifications, gradient conditions are adjusted to resolve the intact peptide from deamidation and oxidation products. Enzymatic digestion followed by peptide mapping confirms the primary sequence and locates specific modifications. Quantitation in biological matrices typically uses liquid chromatography with tandem mass spectrometry after solid-phase extraction. Immunoassays are used less often, since antibody cross-reactivity with closely related peptides can bias results.
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.
Common degradation routes include hydrolysis of labile amide bonds, deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation. Aggregates can form during freeze-thaw cycling, at elevated pH, or when peptide concentration is high. Each route produces characteristic chromatographic or mass shifts that are tracked during stability studies. Whether a given minor impurity alters biological activity is often an open question, and specification limits are typically set on identity and purity rather than on functional data for trace species.
By the time of nominations closing in April 2026, however, Galloway was no longer standing as a constituency candidate in Glasgow Southside, though remained on the regional ballot. He was unsuccessful, as were all other Workers Party candidates in the election. On 27 September 2025, while returning from Moscow through Abu Dhabi, George Galloway and his wife Putri Gayatri Pertiwi were stopped and questioned at Gatwick Airport by the Metropolitan Police's Counter Terrorism Command under the Counter-Terrorism and Border Security Act 2019 and questioned on his opinions of Russia, and China. His party condemned this as "politically motivated intimidation". The Metropolitan Police said "Neither of them were arrested and they were allowed on their way". Following the arrest Galloway entered a "self-imposed exile" in Russia. On the 4 September 2026, the Bank of Scotland closed Galloway's account prompting him to condemn the bank on X, saying "I will not stand by while you use your usurious power to wreck my family life." on the matter. In preparation for the 2026 Greater Manchester mayoral by-election, Galloway announced his candidacy on 19 June 2026. However, when nominations were released on 6 July, he was not listed as a candidate and was not included on the ballot. On the 14 September 2026 George Galloway announced his intention to stand in the 2026 Holborn and St. Pancras by-election on his podcast, MOATS.
== History == in 1957 Lundberg reported on a group of patients with a condition he named myalgia cruris epidemica, seemingly the first description of BACM. Other terms later used include influenza-associated myositis, viral myositis, acute myositis Middleton and colleagues reported on BACM as severe myositis after influenza in 1970. Viral myositis may occur also in later years.
The facility is now heavily damaged, and it soon becomes clear that a new alien race, Race X, has exploited the situation to mount a localized invasion, attacking both human and Xen forces in Black Mesa indiscriminately. Fighting between the black operations units and Race X quickly intensifies. Shephard encounters more stranded Marine units in the wreckage of Black Mesa, and attempts to reach an unknown exit route, encountering heavy resistance from Race X and black operations units. A surviving Black Mesa security guard reveals to Shephard that the black operators intend to detonate a tactical nuclear weapon in the base, thereby totally sealing it off and killing everything in it. After neutralizing the black ops unit guarding the device, Shephard disarms it and proceeds to a nearby storage facility to attempt another escape. As Shephard departs, the G-Man rearms the nuclear device. The storage facility has become a battleground between Race X and the black operation units. Although Shephard manages to evade them, he is informed by another security guard that something very large is coming through an alien portal blocking the exit path. At the portal, Shephard discovers a gene worm, a massive creature facilitating the Race X invasion. Shephard is able to wound the creature enough to force it back through the wormhole, but immediately afterwards he is teleported onto an Osprey by the G-Man. As the G-Man congratulates Shephard on his accomplishments, the nuclear device detonates in the background, destroying Black Mesa.
Sources: en.wikipedia.org
The cell counters of that time used LED screens for result review. In 1982, Medonic AB, another Swedish company with focus on hematology, was founded. The founders, Ingemar Berndtsson and Abraham Bottema, both had a long history and experience in hematology, clinical chemistry, and blood banking engineering. In 1985, Medonic AB launched the Cellanalyzer CA 480 system, its first own-developed cell counter with a built-in display that also showed the cell histograms. When computers began to be incorporated into the analyzers, other brands, like the Swelab analyzers, also came with a display. Both targeting the smaller clinical laboratories, Swelab Instrument AB and Medonic AB were competitors on the decentralized hematology testing market. In the late 90s, both Swelab Instrument AB and Medonic AB were acquired by Boule Diagnostics AB. The company has kept the parallel brands and the analyzers are still manufactured from its facilities in Stockholm, Sweden and supplied under the Swelab and Medonic trademarks for the decentralized hematology testing market. When Coulter was acquired by Beckman, former Coulter employees Dr. Harold R Crews, Andrew C Swanson, and Donald Grantham founded Clinical Diagnostic Solutions, Inc. (CDS) in 1997, focusing on the development and production of generic reagents and control material. In 2004, CDS was acquired by Boule. By this acquisition, Boule came to master the skills of the development and production of both instruments and the consumables included in a complete hematology system.
=== Brand names === Trimipramine is marketed throughout the world mainly under the brand name Surmontil. Other notable brand names of trimipramine have included Herphonal, Rhotrimine, Sapilent, Stangyl, and Tydamine.
Regulatory guidance from the FDA recommends that sponsors of oligonucleotide drug applications assess DDI potential through in vitro transporter studies and, where indirect CYP modulation is plausible, through induction assays, even when direct CYP inhibition is absent.
In a related change, Twitter introduced additional gold and gray checkmarks, used by Verified Organizations and government-affiliated accounts, respectively. Twitter claims that the changes to verification are required to "reduce fraudulent accounts and bots". Twitter users who had been verified through the previous system were known as "legacy verified" accounts; legacy verification was deprecated in April 2023, and stripped from accounts who do not meet the new payment requirements. Musk later implied that he had been personally paying for the X Premium subscriptions of several notable celebrities.
Sources: en.wikipedia.org
== Receptors == In zebrafish, the trace amine-associated receptor 13c (or TAAR13c) has been identified as a high-affinity receptor for cadaverine. In humans, molecular modelling and docking experiments have shown that cadaverine fits into the binding pocket of the human TAAR6 and TAAR8.
=== National Organizing Committee/League of Revolutionaries for a New America (1993) === In the January 1993 issue of Rally, Comrades! "An Open Letter” calling for a new organization was signed by Marian Kramer, President of the National Welfare Rights Union and General Baker, a UAW member and founder of the League of Revolutionary Black Workers. In the same issue of the paper a "Call to form Organizing Committees to establish an organization to educate, organize, and finally lead the masses in the inevitable transformation of our society” was published. It was signed by five activists: Abdul Alkalimat, Nacho Gonzalez, Ethel Long-Scott, John Slaughter and Leona Smith. Also in that issue was a statement by the CLP supporting the Call. The new organization was initially called the National Organizing Committee and later became the League of Revolutionaries for a New America.
==== 1.D Non-ribosomally synthesized channels ==== 1.D.1 The Gramicidin A Channel Family 1.D.2 The Channel-forming Syringomycin Family 1.D.3 The Channel-Forming Syringopeptin Family 1.D.4 The Tolaasin Channel-forming Family 1.D.5 The Alamethicin or Peptaibol Antibiotic Channel-forming Family 1.D.6 The Complexed Poly 3-Hydroxybutyrate Ca2+ Channel (cPHB-CC) Family 1.D.7 The Beticolin Family 1.D.8 The Saponin Family 1.D.9 The Polyglutamine Ion Channel (PG-IC) Family 1.D.10 The Ceramide-forming Channel Family 1.D.11 The Surfactin Family 1.D.12 The Beauvericin (Beauvericin) Family 1.D.13 DNA-delivery Amphipathic Peptide Antibiotics (DAPA) 1.D.14 The Synthetic Leu/Ser Amphipathic Channel-forming Peptide (l/S-SCP) Family 1.D.15 The Daptomycin (Daptomycin) Family 1.D.16 The Synthetic Amphipathic Pore-forming Heptapeptide (SAPH) Family 1.D.17 Combinatorially-designed, Pore-forming, β-sheet Peptide Family 1.D.18 The Pore-forming Guanosine-Bile Acid Conjugate Family 1.D.19 Ca2+ Channel-forming Drug, Digitoxin Family 1.D.20 The Pore-forming Polyene Macrolide Antibiotic/fungal Agent (PMAA) Family 1.D.21 The Lipid Nanopore (LipNP) Family 1.D.22 The Proton-Translocating Carotenoid Pigment, Zeaxanthin Family 1.D.23 Phenylene Ethynylene Pore-forming Antimicrobial (PEPA) Family 1.D.24 The Marine Sponge Polytheonamide B (pTB) Family 1.D.25 The Arylamine Foldamer (AAF) Family 1.D.26 The Dihydrodehydrodiconiferyl alcohol 9'-O-β-D-glucoside (DDDC9G) Family 1.D.27 The Thiourea isosteres Family 1.D.28 The Lipopeptaibol Family 1.D.29 The Macrocyclic Oligocholate Family 1.D.30 The Artificial Hydrazide-appended pillar[5]arene Channels (HAPA-C) Family 1.D.31 The Amphotericin B Family 1.D.32 The Pore-forming Novicidin Family 1.D.33 The Channel-forming Polytheonamide B Family 1.D.34 The Channel-forming Oligoester Bolaamphiphiles 1.D.35 The Pore-forming cyclic Lipodepsipeptide Family 1.D.36 The Oligobornene Ion Channel Family 1.D.37 The Hibicuslide C Family 1.D.38 The Cyclic Peptide Nanotube (cPepNT) Family 1.D.39 The Light-controlled Azobenzene-based Amphiphilic Molecular Ion Channel (AAM-IC) Family 1.D.40 The Protein-induced Lipid Toroidal Pore Family 1.D.41 The Sprotetonate-type Ionophore (Spirohexanolide) Family 1.D.42 The Phe-Arg Tripeptide-Pillar[5]Arene Channel (TPPA-C) Family 1.D.43 The Triazole-tailored Guanosine Dinucleoside Channel (TT-GDN-C) Family 1.D.44 The Synthetic Ion Channel with Redox-active Ferrocene (ICRF) Family 1.D.45 The Sonoporation and Electroporation Membrane Pore (SEMP) Family 1.D.46 The DNA Nanopore (DnaNP) Family 1.D.47 The Pore-forming Synthetic Cyclic Peptide (PSCP) Family 1.D.48 The Pore-forming Syringomycin E Family 1.D.49 The Transmembrane Carotenoid Radical Channel (CRC) Family 1.D.50 The Amphiphilic bis-Catechol Anion Transporter (AC-AT) Family 1.D.51 The Protein Nanopore (ProNP) Family 1.D.52 The Aromatic Oligoamide Macrocycle Nanopore (OmnNP) Family 1.D.53 The alpha, gamma-Peptide Nanotube (a,gPepNT) Family 1.D.54 The potassium-selective Hexyl-Benzoureido-15-Crown-5-Ether Ion Channel (HBEC) Family 1.D.55 The Porphyrin-based Nanopore (PorNP) Family 1.D.56 The Alpha-Aminoisobutyrate (Aib) Oligomeric Nanopore (AibNP) Family 1.D.57 The Lipid Electro-Pore (LEP) Family 1.D.58 The Anion Transporting Prodigiosene (Prodigiosene) Family 1.D.59 The Anion Transporting Perenosin (Perenosin) Family 1.D.60 The Alpha,Gamma-Cyclic Peptide (AGCP) Family 1.D.61 The Anionophoric 2,6-Bis(Benzimidazol-2-yl)Pyridine (ABBP) Family 1.D.62 The Bis-Triazolyl DiGuanosine Derivative Channel-forming (TDG) Family 1.D.63 The Peptide-based Nanopore (PepNP) Family 1.D.64 The Carbon Nanotube (CarNT) Family 1.D.65 The Pore-forming Amphidinol (Amphidinol) Family 1.D.66 The Helical Macromolecule Nanopore (HmmNP) Family 1.D.67 The Crown Ether-modified Helical Peptide Ion Channel (CEHP) Family 1.D.68 The Pore-forming Pleuronic Block Polymer (PPBP) Family 1.D.69 The Conical Nanopore (ConNP) Family 1.D.70 The Metallic (Au/Ag/Pt/graphene) Nanopore (MetNP) Family 1.D.71 The Synthetic TP359 Peptide (TP359) Family 1.D.72 The Chloride Carrier Triazine-based Tripodal Receptor (CCTTR) Family 1.D.73 The Mesoporous Silica Nanopore (SilNP) Family 1.D.74 The Stimulus-responsive Synthetic Rigid p-Octiphenyl Stave Pore (SSROP) Family
There was a prosecutor that asked for an authorization for a prisoner to be freed that guaranteed that he knew where Rui Pedro was. The result: the prisoner went missing. Was not it. It's clear isn't it? They gave the prisoner credit cards. They gave the prisoner a car, gave money and (...) [everything went missing] If that was a lie I would be arrested, because it's easy to arrest journalists, working is hard.The journalist also critiqued the law for having allowed for Mendonça's grandfather to have the role that the Portuguese State had spending money on the Madeleine McCann case. However, Mendonça's grandfather spent his fortune falling for all kinds of scams while searching for the boy. He also questioned the PJ's high rate of success in solving missing children cases, but this one went through three teams of investigation without success. In another interview, he said that the Portuguese State should be on the defendant's bench in Dias' trial, for having left in the open who was, or were the defendants through the fourteen years, which could have affected the testimony of the witnesses in the court.
=== HIV transmission and treatment === In 1981, while working at UCSF in a lab that could perform the immunologic tests needed to detect immunodeficiency in AIDS patients, Ammann observed immunodeficiency disorders in children that mirrored those of gay men who had contracted the Human Immunodeficiency Virus. Ammann's investigations into the cause of the symptoms led him to identify two new means of transmission, in utero mother to infant and blood transfusions. With the medical community wanting not to believe that AIDS could affect infants, Ammann's initial publication blood transfusion infection was rejected by prominent medical journals. This discovery changed the perception of HIV/AIDS as an epidemic solely within the gay community. In 1985, Ammann left his position at UCSF in order to work with the biotechnology firm, Genentech. There he developed clinical products focused on HIV/AIDS, and although while with Genentech a successful vaccine was not developed, the discoveries made by Ammann's research team were used by other researchers in a partially successful study performed in Thailand in 2009. In 1994, Ammann was selected to become a member of the Presidential National AIDS Task Force on Drug and Vaccine Development. Three years later, in 1996, he was recognized by POZ magazine as one of the fifty most influential AIDS researchers.
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 is a dual GIP and GLP-1 receptor agonist, frequently grouped with incretin-based peptide therapeutics. It is a peptide rather than a small molecule and is given by subcutaneous injection.