This is a working overview of DAC, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-05-03. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| 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 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.
CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
At the pituitary, the peptide binds the growth hormone-releasing hormone receptor on somatotroph cells. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone. Somatostatin and other hypothalamic signals modulate this response. Negative feedback from insulin-like growth factor 1 also influences output. The same regulatory architecture operates with the native hormone. Whether the synthetic analog alters feedback dynamics over repeated exposure remains an open question. Most published receptor work uses cell models rather than intact human systems.
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.
=== Mark Conner-Healy === Mark Conner-Healy is played by Ames McNamara. The younger of Darlene's two children, Mark is a 10-year-old boy with a strong interest in fashion. His interest in things traditionally feminine, such as wearing makeup and skirts, is somewhat worrisome to his grandparents, with Roseanne worried that Mark will be bullied by his narrow-minded peers and Dan feeling that he needs to persuade the youngster to take on more masculine traits. Noticing a classmate make a snide comment to Mark on his first day at school in Lanford, Roseanne threatens his classmates by telling them she is a witch, while Dan gives Mark a pocket knife, which ultimately results in him being called to the principal's office and sent home from school for the day, much to Darlene's chagrin. Despite Roseanne and Dan's concerns, they express support and love for him. Mark is named after his deceased uncle, Mark Healy.
=== Batten disease === Milasen is a novel individualized therapeutic agent that was designed and approved by the FDA for the treatment of Batten disease. This therapy serves as an example of personalized medicine. In 2019, a report was published detailing the development of milasen, an antisense oligonucleotide drug for Batten disease, under an expanded-access investigational clinical protocol authorized by the Food and Drug Administration (FDA). Milasen "itself remains an investigational drug, and it is not suited for the treatment of other patients with Batten's disease" because it was customized for a single patient's specific mutation. However it is an example of individualized genomic medicine therapeutical intervention.
===== Supporters ===== Two stags Or attired and unguled Azure each gorged with a collar of braid Gules Argent and Azure standing upon a representation of the Scarborough Bluffs proper rising above the waters of Lake Ontario Azure and Argent;
In 1813, George III was restored to his Hanoverian territories, and in October 1814, they were constituted as the independent Kingdom of Hanover at the Congress of Vienna. The personal union with the United Kingdom ended in 1837 on the accession of Queen Victoria because the succession laws in Hanover, based on semi-Salic law, prevented a female from inheriting the title if there was a surviving male heir. In the United Kingdom, a male took precedence only over his own sisters.
Sources: en.wikipedia.org
Simple compounds which are converted into other compounds, usually as part of a multiple step reaction pathway. Two examples of this type of reaction occur during the formation of nucleic acids and the charging of tRNA prior to translation. For some of these steps, chemical energy is required:
In the summer of 2021, Democrats in the Texas House of Representatives, including Talarico, organized a quorum break in an attempt to stop the passage of the Election Integrity Protection Act of 2021. They flew to Washington, D.C., to lobby the Senate to pass the John Lewis Voting Rights Act and the For the People Act, which would have superseded parts of the state legislation. Talarico was one of the first Democrats to return to Texas as the quorum break progressed, arguing that the effort had achieved its goals, that Democrats needed to reduce the harm of Republican legislation, and that an indefinite quorum break was unsustainable. Some representatives who remained in D.C. strongly criticized him for this. Quorum was eventually reestablished and the legislation passed. At the end of the legislative session, Texas Monthly magazine named Talarico one of the Top 10 Best Legislators.
== Education == Burnham earned her Ph.D. in medical sciences at the University of Alberta in 2007. Later, she pursued fellowship training in clinical microbiology at Washington University in St. Louis, which she completed in 2009.
Sources: en.wikipedia.org
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The university consolidated its physicians' practice plans and transferred them, along with the university's hospital management functions, to UPMC, with UPMC providing ongoing financial support to the university and its academic missions in return. The result was a mutually exclusive partnership formalized by a series of interrelated agreements and mutual executive oversights, which shares numerous board members. This created a decision-making model in which UPMC oversees clinical activity, while the University of Pittsburgh guards academic priorities, particularly faculty-based research. Expansion of UPMC continued in 2001 as Children's Hospital of Pittsburgh began merging with UPMC. Since then, UPMC merged with Mercy Hospital in 2008; opened new Children's Hospital facilities in 2009; integrated Hamot Medical Center in Erie, Pennsylvania, in 2011, Altoona Regional Health System in Altoona, Pennsylvania, in 2013, and Jameson Health System in New Castle, Pennsylvania, in 2016; along with continued expansion of overseas operations and for-profit business ventures. In October 2016, Susquehanna Health, a four-hospital system in north central Pennsylvania, became the first domestic hospital outside Western Pennsylvania to join the UPMC system. UPMC Susquehanna merged with two additional community hospitals in October 2017. In December 2016, WCA Hospital of Jamestown, New York, became the first domestic hospital outside of Pennsylvania in the UPMC system.
== Amine protection == Benzyl chloroformate is commonly used in organic synthesis for the introduction of the benzyloxycarbonyl (formerly called carboxybenzyl) protecting group for amines. The protecting group is abbreviated Cbz or Z (in honor of discoverer Zervas), hence the alternative shorthand designation for benzyl chloroformate as Cbz-Cl or Z-Cl. Benzyloxycarbonyl is a key protecting group for amines, suppressing the nucleophilic and basic properties of the N lone pair. This "reactivity masking" property, along with the ability to prevent racemization of Z-protected amines, made the Z group the basis of the Begmann-Zervas synthesis of oligopeptides (1932) where the following general reaction is performed to protect the N-terminus of a serially growing oligopeptide chain:
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.
The two share the same 29-amino-acid backbone. CJC-1295 carries an additional albumin-binding moiety that markedly extends its residence time in circulation, while the form without that moiety clears faster. Literature sometimes applies the name loosely to either variant.