The short version of GRF(1-29) fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.
Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.
==== Insecticides ==== RNAi is under development as an insecticide, employing multiple approaches, including genetic engineering and topical application. Cells in the midgut of some insects take up the dsRNA molecules in the process referred to as environmental RNAi. In some insects the effect is systemic as the signal spreads throughout the insect's body (referred to as systemic RNAi). Animals exposed to RNAi at doses millions of times higher than anticipated human exposure levels show no adverse effects. RNAi has varying effects in different species of Lepidoptera (butterflies and moths). Drosophila spp., Bombyx mori, Locusta spp., Spodoptera spp., Tribolium castaneum, Nilaparvata lugens, Helicoverpa armigera, and Apis mellifera are models that have been widely used to learn how RNAi works within particular taxa of insects. Musca domestica has two Ago2 genes and Glossina morsitans three, as found by Lewis et al. 2016 and Hain et al. 2010. In the case of the miRNA pathway Diuraphis noxia has two Ago1s, M. domestica two Dcr1s, Acyrthosiphon pisum two each of Ago1 and Loqs and Dcr1 and four of Pasha. While in the piRNA, G. morsitans and A. pisum have two or three Ago3s each. This has led to identification of future insecticide development targets, and the modes of action and reasons for insecticide resistance of other insecticides.
Cardiolipin (CL) is a kind of diphosphatidylglycerol lipid. Two phosphatidic acid moieties connect with a glycerol backbone in the center to form a dimeric structure. So it has four alkyl groups and potentially carries two negative charges. As there are four distinct alkyl chains in cardiolipin, the potential for complexity of this molecule species is enormous. However, in most animal tissues, cardiolipin contains 18-carbon fatty alkyl chains with 2 unsaturated bonds on each of them. It has been proposed that the (18:2)4 acyl chain configuration is an important structural requirement for the high affinity of CL to inner membrane proteins in mammalian mitochondria. However, studies with isolated enzyme preparations indicate that its importance may vary depending on the protein examined. In vitro experiments have shown that CL has high affinity for curved membrane regions. Since there are two phosphates in the molecule, each of them can bond with one proton. Although it has a symmetric structure, ionizing one phosphate happens at a very different levels of acidity than ionizing both: pK1 = 3 and pK2 > 7.5. So under normal physiological conditions (wherein pH is around 7), the molecule may carry only one negative charge. The hydroxyl groups (–OH and –O−) on phosphate would form a stable intramolecular hydrogen bond with the centered glycerol's hydroxyl group, thus forming a bicyclic resonance structure. This structure traps one proton, which is quite helpful for oxidative phosphorylation.
== Working with FASTA files == A plethora of user-friendly scripts are available from the community to perform FASTA file manipulations. Online toolboxes, such as FaBox or the FASTX-Toolkit within Galaxy servers, are also available. These can be used to segregate sequence headers/identifiers, rename them, shorten them, or extract sequences of interest from large FASTA files based on a list of wanted identifiers (among other available functions). A tree-based approach to sorting multi-FASTA files (TREE2FASTA) also exists based on the coloring and/or annotation of sequences of interest in the FigTree viewer. Additionally, the Bioconductor Biostrings package can be used to read and manipulate FASTA files in R. Several online format converters exist to rapidly reformat multi-FASTA files to different formats (e.g. NEXUS, PHYLIP) for use with different phylogenetic programs, such as the converter available on phylogeny.fr.
Sources: en.wikipedia.org
Beverly Gail Allitt (born 4 October 1968) is an English serial killer who was convicted of murdering three infants and an 11-year-old boy, attempting to murder three others, and causing grievous bodily harm to six more at Grantham and Kesteven Hospital, Lincolnshire, between February and April 1991. She committed the murders as a state enrolled nurse on the hospital's children's ward. Allitt administered large doses of insulin to at least two of her victims and a large air bubble was found in the body of another, but police were initially unable to establish how all of the attacks were carried out. In May 1993, Allitt received 13 life sentences at Nottingham Crown Court. The sentencing judge, Mr Justice David Latham, told Allitt that she was "a serious danger" to others and was unlikely ever to be considered safe enough to be released. Allitt is currently detained at Rampton Secure Hospital in Nottinghamshire. She became eligible for release on parole after her minimum tariff of 30 years' imprisonment expired in November 2021.
=== Contrast agents === Chelate complexes of gadolinium are often used as contrast agents in MRI scans, although iron particle and manganese chelate complexes have also been explored. Bifunctional chelate complexes of zirconium, gallium, fluorine, copper, yttrium, bromine, or iodine are often used for conjugation to monoclonal antibodies for use in antibody-based PET imaging. These chelate complexes often employ the usage of hexadentate ligands such as desferrioxamine B (DFO), according to Meijs et al., and the gadolinium complexes often employ the usage of octadentate ligands such as DTPA, according to Desreux et al. Auranofin, a chelate complex of gold, is used in the treatment of rheumatoid arthritis, and penicillamine, which forms chelate complexes of copper, is used in the treatment of Wilson's disease and cystinuria, as well as refractory rheumatoid arthritis.
With the dissolution of the Soviet Union and the Fall of Communism, there was a split among Marxist–Leninists between those hardline Marxist–Leninists, sometimes referred to in the media as neo-Stalinists, which remained committed to orthodox Marxism–Leninism, and those democratic Marxist–Leninists which continued to work within the liberal-democratic process for a democratic road to socialism, while many other ruling Marxist–Leninist parties became closer to democratic socialist and social democratic parties. Outside Communist states, reformed Marxist–Leninist communist parties have led or been part of left-leaning coalitions, including in the former Eastern Bloc. In Nepal, Marxist–Leninists (CPN UML and Nepal Communist Party) were part of the 1st Nepalese Constituent Assembly, which abolished the monarchy in 2008 and turned the country into a federal liberal-democratic republic, and have democratically shared power with Maoists (CPN Maoist), social democrats (Nepali Congress), and others as part of their People's Multiparty Democracy.
Sources: en.wikipedia.org
The yeast has a negative effect on the bacteria that normally produce antibiotics to kill the parasite, so may affect the ants' health by allowing the parasite to spread. A different yeast species is grown by fungus-growing ants of the genus Cyphomyrmex. Certain strains of some species of yeasts produce proteins called yeast killer toxins that allow them to eliminate competing strains. (See main article on killer yeast.) This can cause problems for winemaking but could potentially also be used to advantage by using killer toxin-producing strains to make the wine. Yeast killer toxins may also have medical applications in treating yeast infections (see "Pathogenic yeasts" section below). Marine yeasts, defined as the yeasts that are isolated from marine environments, are able to grow better on a medium prepared using seawater rather than freshwater. The first marine yeasts were isolated by Bernhard Fischer in 1894 from the Atlantic Ocean, and those were identified as Torula sp. and Mycoderma sp. Following this discovery, various other marine yeasts have been isolated from around the world from different sources, including seawater, seaweeds, marine fish and mammals. Among these isolates, some marine yeasts originated from terrestrial habitats (grouped as facultative marine yeast), which were brought to and survived in marine environments. The other marine yeasts were grouped as obligate or indigenous marine yeasts, which are confined to marine habitats. However, no sufficient evidence has been found to explain the indispensability of seawater for obligate marine yeasts.
=== Cigarette smoke === Connections exist between acrolein gas in the smoke from tobacco cigarettes and the risk of lung cancer. Acrolein is one of seven toxicants in cigarette smoke that are most associated with respiratory tract carcinogenesis. The mechanism of action of acrolein appears to involve induction of increased reactive oxygen species and DNA damage related to oxidative stress. Acrolein is the most significant contributor to non-cancer related health risks in cigarette smoke, contributing 40 times more than the next component, hydrogen cyanide. The acrolein content in cigarette smoke depends on the type of cigarette and added glycerin, making up to 220 μg acrolein per cigarette. Importantly, while the concentration of the constituents in mainstream smoke can be reduced by filters, this has no significant effect on the composition of the side-stream smoke where acrolein usually resides, and which is inhaled by passive smoking. E-cigarettes, used normally, only generate "negligible" levels of acrolein (less than 10 μg "per puff").
The album was originally scheduled for worldwide release in 2017, but was postponed in lieu of Live in Chicago; however, it was only released in Japan in September 2017, with a bonus disc with recordings from the band's tour there in December 2015. The worldwide release added a performance of "Fracture", plus three pieces drawn from the nightly Fripp-composed introductory soundscapes with improvisations by Collins and Levin: these pieces were arranged and realised by David Singleton, reflecting similar work he'd performed for Thrakattak twenty years earlier. On 20 October 2018, a further live album/video was released, Meltdown: Live in Mexico City, recorded during dates in July 2017.
Sources: en.wikipedia.org
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
Mass spectrometry establishes whether the observed molecular weight matches the calculated sequence mass. Chromatographic retention and fragment mapping add further confidence about sequence and composition. A single technique alone is rarely treated as sufficient evidence of identity.