A practical reference on DAC group: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-08. Anything still debated is marked as such rather than presented as settled.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
Purity is most often assessed by reversed-phase high-performance liquid chromatography, reported as a percentage of total peak area. Identity is confirmed by mass spectrometry, which yields a molecular ion consistent with the expected sequence. Amino acid analysis and peptide mapping provide additional characterization. Reported purity values are method-dependent, so figures from different laboratories are not always directly comparable without details of column, gradient, and detection wavelength.
Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
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.
Linked-read sequencing can facilitate de novo genome assembly, which involves reconstructing a genome from scratch without any prior reference. Linked-read sequencing enables assembly of large genomic regions, and helps improve the completeness and contiguity of the resulting genome. This can be particularly useful for studying organisms that lack a high-quality reference genome, such as non-model organisms or organisms with complex genomes. Many scientists have been using linked-read sequencing technology for de novo genome assembly recently in a variety of organisms, including humans, plants, and animals. For example, Dr. Evan Eichler and his research group used linked-read sequencing to assemble genome of orangutan, which had previously been difficult to study due to its complex genome. The resulting genome assembly helped scientists to study new insights into the evolutionary history of primates and the genetic basis of human diseases. Also, the aligned or assembled reads can be used for other genetic investigations or downstream analysis, such as haplotype phasing.
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Ipragliflozin (INN, trade names Suglat) is a pharmaceutical drug for treatment of type 2 diabetes. Ipragliflozin, jointly developed by Astellas Pharma and Kotobuki Pharmaceutical, was approved in Japan on January 17, 2014, and in Russia on May 22, 2019. Ipragliflozin is a Sodium/glucose cotransporter 2 (SGLT2) inhibitor (gliflozin). These membrane proteins are on the cell surface and transfer glucose into the cells. SGLT2 is one subtype of SGLTs and plays a key role in the reuptake of glucose in the proximal tubule of the kidneys. Ipragliflozin reduces blood glucose levels by inhibiting the reuptake of glucose by selectively inhibiting SGLT2.
In July 2009, Mohammad Sajjadur Rahman noted that Russia's role in the Caucasus region in the 1990s "transformed the separatist conflicts into a dispute between Georgia and Russia" and that "Realism, the most dominant theory of International Relations, can be applied in analyzing Russian behavior" in the conflict which was the first Russian military action since the Soviet–Afghan War. Rahman denied the claim that Russia was defending itself, explaining that "long before the war broke out, Russia had established the infrastructure and logistical support for a military invasion" and decision to go to war was "guided by a number of geopolitical interests that Russia sought to advance through a decisive victory", such as "Putins’ evident desire to elevate Russia's Great Power image". However, "the war exposed Russia's failure to accomplish political objectives without recourse to violence." Rahman summarized that "the causes of the August war were indeed complex and multifaceted" and the failure of the West "in deescalating the tension also contributed to the outbreak of this limited war."
Sources: en.wikipedia.org
== Fictional spy stories == Cloak and dagger stories became part of the popular culture of the Cold War in both East and West, with innumerable novels and movies that showed how polarized and dangerous the world was. Soviet audiences were thrilled by spy stories showing how their KGB agents protected the motherland by foiling dirty work by the intelligence agencies of the United States, United Kingdom, and Israel. After 1963, Hollywood increasingly depicted the CIA as clowns (as in the comedy TV series Get Smart) or villains (as in Oliver Stone's 1992 film JFK). Ian Fleming's infamous spy novels about the MI6 agent James Bond also referenced elements of the Cold War when being adapted into films. One example of this includes the first Bond film, Dr. No, which was released in 1962 and used the Cuban Missile Crisis as a plot base. However, Cuba was substituted for Jamaica in the film.
== Health effects == Due to the elevated levels of nitrites, consuming salted fish increases risk of stomach cancer and nasopharyngeal cancer. The International Agency for Research on Cancer classify salted fish (Chinese-style) as a Group 1 carcinogen.
== Teams == For the 2019 season the following teams were not listed by the UCI at UCI Women's team level: Alasayl Cycling Team, Cylance Pro Cycling, Experza–Footlogix, S.C. Michela Fanini Rox, Storey Racing, UnitedHealthcare and Wiggle High5.
Sources: en.wikipedia.org
Ellen McLain provides the voice for the Combine Overwatch announcer and dispatcher in Half-Life 2 and its episodic expansions and their virtual reality prequel Half-Life: Alyx. Combine soldiers in Half-Life: Alyx are voiced by actors including Rich Sommer, Isaac C. Singleton Jr., Jason Vande Brake, Michael Schwalbe, Rajia Baroudi, and Rick Zieff.
==== Carbon bound hydrogen exchange ==== For some time, researchers believed that large hydrocarbon molecules were impervious to hydrogen exchange, but recent work has identified many reactions that allow isotope reordering. The isotopic exchange becomes relevant at geologic time scales and has impacted work of biologists studying lipid biomarkers, and geologists studying ancient oil. Reactions responsible for exchange include
The wide-spread interest in the very remarkable specimen of the giant squid, now lying on the beach a few miles below the city, is mainly due to its enormous size. It is believed to be the largest specimen ever found. Its great size and immense weight have thus far prevented its being moved for a more careful examination. A dozen men with blocks and tackle not being able even to turn it over. Another effort will be made with more extensive apparatus by which it is hoped to drag it from the pit in which it now lies and placing it higher up on the beach so that a careful and thorough examination in the interest of science can be made and the exact species determined. Professor Verrill of Yale and Profs. True and Dale [Dall] of the Smithsonian are in constant correspondence with Dr. DeWitt Webb, President of the St. Augustine Scientific, Literary and Historical Society, in regard to it. Several photographs have been taken of it, but owing to its position, these have not been satisfactory. Mrs. John L. Wilson believes it to belong to an extinct species. Its hide is three and a half inches thick and its head is covered by a hood that prevents examination. Apparently it is a mass of cartilage and may have been dead in the water many days before it washed ashore on Anastasia Island. In the February issue of the American Journal of Science, Verrill even gave the animal a scientific name, Octopus giganteus (Verrill, 1897). He also added:
Sources: en.wikipedia.org
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.