DAC group raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-10-16 and is reviewed periodically as new material appears.
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.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
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 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.
| 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 |
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
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.
Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
=== CDK independent functions === Independent of CDK, cyclin D1 binds to nuclear receptors (including estrogen receptor α, thyroid hormone receptor, PPARγ and AR) to regulate cell proliferation, growth, and differentiation. Cyclin D1 also binds to histone acetylases and histone deacetylases to regulate cell proliferation and cell differentiation genes in the early to mid-G1 phase.
==== Methadone clinics ==== In the United States, prescription of methadone requires intensive monitoring and must be obtained in-person from an Opioid Treatment Program—colloquially known as a 'methadone clinic'—when prescribed for opioid use disorder (OUD). According to federal laws, methadone cannot be prescribed by a doctor and obtained from a pharmacy to treat addiction. Because of its long half-life, methadone is almost invariably prescribed to be taken in a single daily dose. At nearly all methadone clinics in the US, patients must visit a clinic to receive and take their dose under the supervision of a nurse. Patients earn take home bottles with their daily dose, by providing clean drug tests and doing therapy. These bottles will be taken away if they provide a dirty drug test, or break clinic rules. They can be earned back. Both patients who are new to methadone treatment and high-risk patients—such as those who are using drugs and alcohol, including cannabis in some states—must visit the clinic daily.
t1/2: Biological half-life tmax: Time to achieve maximum plasma concentration pKi: the measurement of ligand binding affinity Methylnaltrexone bromide has poor oral bioavailability, and for that reason, every other day it is administered subcutaneously. About half of the dose is excreted in the urine and somewhat less in feces with 85% eliminated unchanged. Alvimopan has considerable low bioavailability (6%) due to its high binding affinity and low dissociation rate. Essentially, alvimopan is mediated by biliary secretion with an average plasma clearance of 400 ml/min. Metabolism of alvimopan is via intestinal flora resulting in hydrolysis of alvimopan to the active amide metabolite (ADL 08-0011). However, the metabolite is considered clinically irrelevant due to its low binding affinity. When naloxegol is given with a fatty meal, absorption increases. Clearance is mostly via hepatic metabolism (P450-CYP3A) with unknown actions of the metabolites. Naloxegol has small fragments eliminated by renal excretion. Naldemedine metabolites mainly via CYP3A to nor-naldemedine, it also metabolites via UDP-glucuronosyltransferase 1A3 to naldemedine 3-G, but in a lesser extent. Those metabolites are both opioid receptor antagonists but are less potent than the parent compound.
Sources: en.wikipedia.org
== Changes for 2020 exam == The Central Board of Secondary Education (CBSE) has been conducting two separate Mathematics examinations in the class 10 board examination, starting from the 2020 session. Mathematics exam till 2019 was Mathematics (Standard), and an easier version, Mathematics (Basic), has been introduced. The option to choose mathematics is available on the registration form for the Class 10 CBSE board examination. Candidates are required to select their test choice while filling out the registration form for the CBSE Class 10 board examination 2020. Minister of Education, MoE (previously Minister of Human Resource Department, HRD), amid the coronavirus outbreak had ordered rescheduling of pending examinations. The exams rescheduled were to be conducted between 1 and 15 July. On 26 June, CBSE released as circular which cancelled the remaining exams and give scores based on the scores of the exams already taken by students. Some students of Delhi who were able to provide three or fewer exams were scored as per their performance in internal exams. This decision came after a judicial ruling.
Heavy menstrual periods Endometriosis and chronic pelvic pain Adenomyosis and dysmenorrhea Anemia Endometrial hyperplasia (especially in pre-menopausal people who wish to maintain fertility in the treatment of endometrial hyperplasia) In some cases, use of a hormonal IUD may prevent a need for a hysterectomy. Advantages:
=== Detection of protein phosphorylation === Phosphorylation means the posttranslational addition of a phosphate group to specific amino acids of proteins, and such modification can lead to a drastic change in the stability or the function of a protein in the cell. Protein phosphorylation can be detected on an autoradiograph, after incubating the protein in vitro with the appropriate kinase and γ-32P-ATP. The radiolabeled phosphate of latter is incorporated into the protein which is isolated via SDS-PAGE and visualized on an autoradiograph of the gel. (See figure 3. of a recent study showing that CREB-binding protein is phosphorylated by HIPK2.)
=== COVID-19 misinformation === During the COVID-19 pandemic, Ayyadurai used social media to spread various conspiracy theories and misinformation about the pandemic. In January 2020, he claimed that COVID-19 was patented by the Pirbright Institute, but the patent he referenced relates to avian coronavirus, which infects birds, not SARS-CoV-2, the virus responsible for the pandemic. Ayyadurai defined COVID-19 as "an overactive dysfunctional immune system that overreacts and that's what causes damage to the body", and claimed that vitamin C could be used to treat it. He alleged that COVID-19 was spread by the "deep state" and accused Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, of being a "Deep State Plant". Ayyadurai called for Fauci to be fired and his supporters lobbied for Fauci to be replaced by Ayyadurai. In March 2020, Ayyadurai published an open letter to then-U.S. President Donald Trump, writing that a national lockdown was unnecessary and advocated that large doses of vitamins could prevent and cure COVID-19. In April 2020, Politico and Vanity Fair reported that QAnon supporter DeAnna Lorraine recommended that Ayyadurai be included in COVID-19 discussions at Donald Trump's White House.
Sources: en.wikipedia.org
The Hidden - Puts one player (called The Hidden) as an invisible genetically modified human against a team of SWAT-like operatives called the Infinitum Research Intercept Squad, (IRIS) with regular human attributes but a selection of weapons to choose. The IRIS team's objective is to hunt down the Hidden, while the Hidden attempts to stalk and kill the IRIS team without being detected. Hidden: Source won Mod DB's "Fourth Place, Mod of the Year" in 2006, "Editors' Choice for Ambience" in 2006, and "Editors' Choice for Multiplayer" in 2005. Insurgency: Modern Infantry Combat - Is a total conversion mod for Valve's Source engine. Insurgency is a multiplayer, tactical first person shooter, and implements elements of realism, in an attempt to increase player immersion and promote teamwork. The game is primarily set in the Iraq war, however some maps are set in Afghanistan, and future updates are planned to expand the setting into a hypothetical conflict in Kosovo and other theatres. Insurgency received the Player's Choice 2007 "Mod of the Year" award from ModDB, as well as the "Best Source Mod of 2007" Gold Award from Steamfriends. Iron Grip: The Oppression - A first-person shooter/real-time strategy hybrid set within the fictional Iron Grip universe in a predominantly urban setting. The game pits two separate factions against each other: the Rahmos and the Resistance. Playing as the Rahmos gives at least one player control of an array of AI-controlled NPCs in a top-down real-time strategy perspective.
The formed PCT then undergoes post-translational modifications, resulting in the production small peptides and mature CT by removal of the C-terminal glycine from the immature CT by peptidylglycine α-amidating monooxygenase (PAM). In a microbial infected individual, non-neuroendocrine tissue also secretes PCT by expression of CALC-1. A microbial infection induces a substantial increase in the expression of CALC-1, leading to the production of PCT in all differentiated cell types. The function of PCT synthesized in nonneuroendocrine tissue due to a microbial infection is currently unknown, but its detection aids in the differentiation of inflammatory processes.
Alexandre Marc Raymond was born on 22 January 1872 in Constantinople, in Turkey, then part of the Ottoman Empire. He was the son of Marc Raymond, architect, born in Constantinople in 1846, and Rose Valsamaki, Greek Orthodox, born in Cephalonia. In 1894, he began studying at Sanayi-i Nefise Mektebi (School of Fine Arts) in Constantinople where he was a student of Alexander Vallaury.
=== DAPI === DAPI is a fluorescent nuclear stain, excited by ultraviolet light and showing strong blue fluorescence when bound to DNA. DAPI binds with A=T rich repeats of chromosomes. DAPI is also not visible with regular transmission microscopy. It may be used in living or fixed cells. DAPI-stained cells are especially appropriate for cell counting.
=== Neuromuscular adaptations === Strength training is not only associated with an increase in muscle mass, but also an improvement in the nervous system's ability to recruit muscle fibers and activate them at a faster rate. Neural adaptations can occur in the motor cortex, the spinal cord, and/or neuromuscular junctions. The initial significant improvements in strength amongst new lifters are a result of increased neural drive, motor unit synchronization, motor unit excitability, rate of force development, muscle fiber conduction velocity, and motor unit discharge rate. Together, these improvements provide an increase in strength separate from muscle hypertrophy. Typically, the main barbell lifts – squat, bench, and deadlift – are performed with a full range of motion, which provides the greatest neuromuscular improvements compared to one-third or two-thirds range of motion. However, there are reasons to perform these lifts with less range of motion, particularly in the powerlifting community. By limiting range of motion, lifters can target a specific joint angle in order to improve their sticking points by training their neural drive. Neuromuscular adaptations are critical for the development of strength, but are especially important in the aging adult population, as the decline in neuromuscular function is roughly three times as great (≈3% per year) as the loss of muscle mass (≈1% per year). By staying active and following a resistance training program, older adults can maintain their movement, stability, balance, and independence.
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.
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.