peptide mapping comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-11-18. Numbers and descriptions here follow the published literature rather than marketing material.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
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.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
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.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
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Commercialized as the Model 470A protein sequencer, it allowed scientists to determine partial amino acid sequences of proteins that had not previously been accessible, characterizing new proteins and better understanding their activity, function, and effects in therapeutics. These discoveries had significant ramifications in biology, medicine, and pharmacology. The first automated DNA synthesizer resulted from a collaboration with Marvin H. Caruthers of the University of Colorado Boulder, and was based on Caruthers' work elucidating the chemistry of phosphoramidite oligonucleotide synthesis. Caltech staff scientist Suzanna J. Horvath worked with Hood and Hunkapiller to learn Caruthers' techniques in order to design a prototype that automated the repetitive steps involved in Caruthers' method for DNA synthesis. The resulting prototype was capable of forming short pieces of DNA called oligonucleotides, which could be used in DNA mapping and gene identification. The first commercial phosphoramidite DNA synthesizer was developed from this prototype by Applied Biosystems, who installed the first Model 380A in Caruthers' lab at the University of Colorado in December 1982, before beginning official commercial shipment of the new instrument. Revolutionizing the field of molecular biology, the DNA synthesizer enabled biologists to synthesize DNA fragments for cloning and other genetic manipulations. Molecular biologists were able to produce DNA probes and primers for use in DNA sequencing and mapping, gene cloning, and gene synthesis.
Sources: en.wikipedia.org
=== Cancer === Point mutations in multiple tumor suppressor proteins cause cancer. For instance, point mutations in Adenomatous Polyposis Coli promote tumorigenesis. A novel assay, Fast parallel proteolysis (FASTpp), might help swift screening of specific stability defects in individual cancer patients.
The ninth generation BJ Familia was introduced on 9 June 1998 and released on 29 September 1998 as a 1999 model. Body styles included a four-door saloon and a five-door S-Wagon (sold as the Protegé5 in the United States and Canada, 323F in Europe, and as the Astina NU in some Asian countries). In Japan there was also a traditional five-door light van (station wagon for commercial use) sold under the Familia nameplate, but this car was simply a rebadged Nissan. A 4EC automatic transmission and two five-speed manual transmissions were available. All-wheel drive is optional. The Japanese Mazda Familia had all-wheel drive as an option. In North America, the ES's engine was still 1.8 liters, but for the eighth generation it was a smaller version of the 626's engine (the FP) rather than the sportier engine shared with the Miata which had been used previously. The rear disc brakes of the ES were downgraded to drums. Mazda 323s were used as police cars by some police departments such as the Singapore Police Force as Fast Response Cars (FRCs) until they were retired in 2016. The Familia Van and Familia Business Wagon were introduced for 2000, and continued to be supplied by Nissan under an OEM deal, based on the Nissan AD.
=== Ko–Ku === Arthur Kornberg (1918–2007). American biochemist at Stanford, who won the Nobel Prize in Chemistry (1959) for discovery of DNA polymerase. Member Natl. Acad. Sci. USA. Sir Hans Kornberg FRS (1928–2019). British biochemist at Cambridge University, known for research in microbial biochemistry. Member Natl. Acad. Sci. USA. Roger D. Kornberg (b. 1947). American biochemist at Stanford, who won the Nobel Prize in Chemistry (2006) for studies on RNA polymerase. Member Natl. Acad. Sci. USA. Sylvy Kornberg (1917–1986). American biochemist at Stanford, who worked in collaboration with Arthur Kornberg on DNA replication and polyphosphate synthesis. Thomas B. Kornberg (b. 1948). American biochemist at UC San Francisco, who works on Drosophila melanogaster development. Daniel E. Koshland Jr. (1920–2007). American biochemist at UC Berkeley, known for protein flexibility (induced fit). Member Natl. Acad. Sci. USA Douglas Koshland (b. 1953). Molecular and cellular biologist at UC Berkeley. Edwin Gerhard Krebs (1918–2009) was an American biochemist at the University of Washington, Seattle, and Nobel prizewinner, known for the study of phosphorylation/hydrolysis cycling. Sir Hans Adolf Krebs FRS (1900–1981). British biochemist at Sheffield and Oxford, known for many advances in metabolism, most notably the tricarboxylate ("Krebs") cycle. Nobel Prize in Physiology or Medicine (1953). Charles Kurland (b. 1936) Member of the Royal Swedish Academy of Sciences. Swedish biochemist at Lund University, of American origin, known for work on the tree of life.
Sources: en.wikipedia.org
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.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
It is a synthetic peptide analogue of growth hormone-releasing hormone. Four substitutions in its sequence make it more resistant to enzymatic degradation than the natural hormone. In the version carrying a drug affinity complex, the peptide binds albumin and remains in circulation for days.