If you have been reading about GRF(1-29) and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.
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.
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.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
The sickness was aggravated by the intense heat and the appalling effluvium arising from the 90 Siberian sledge-dogs we had on deck. These dogs were procured from the Samoyedes in the North of Siberia and were the first dogs ever introduced in Antarctic exploration. On the return trip, the dogs were left on Native Island, New Zealand. Due to quarantine requirements, many of the dogs were killed but a few remained. Nine of the remaining dogs were bought by Ernest Shackleton. Robert Falcon Scott brought twenty Samoyeds with him during his 1902 journey. The dogs struggled under the conditions Scott placed them in, with four dogs pulling heavily loaded sleds through 45 cm (18 in) of snow with bleeding feet. Scott blamed their failure on rotten dried fish.
== Early life and education == Born in 1953 and raised in Dearborn, Michigan, Tippett is an alumnus of Kalamazoo College and holds a Ph.D. and M.D. from Case Western Reserve University School of Medicine. He studied at the Rockefeller University in New York under Nobel Prize winner Robert Bruce Merrifield, directing his doctoral research efforts toward the metabolic indicators of peptide synthesis. He completed his internship and residency in Internal Medicine at Cleveland Metropolitan General Hospital, and spent 1975-1985 engaged in biochemical research.
It was determined that subjects that received three daily doses of 40 micrograms/kg demonstrated adequate production of epithelial cells in the buccal mucosa. Predicted elevation in amylase and lipase were also determined. Study 20010192 (Randomized, double-blind, placebo-controlled, dose-escalation). Intended to determine safety and tolerability, pharmacokinetic and pharmacodynamics properties of the drug versus a placebo by utilization of a single IV dose (ranging from 60 to 250 micrograms/kg) in 84 healthy volunteers. It was determined that after the first 30 minutes (after IV dose was administered) a rapid decline in concentration occurred, followed by a subsequent plateau once 1.5 hours had been achieved. A decline in concentration was consistently observed once six hours post-dose had been reached. It was also noted that with a four-fold increase in dose, a three-fold increase in AUC was achieved. Half-life values of 4–6 hours were noted; extravascular distribution of the drug was noted as well.
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== Function == In myocytes, sarcomeres adhere to the sarcolemma via costameres, which align at Z-discs and M-lines. The two primary cytoskeletal components of costameres are desmin intermediate filaments and gamma-actin microfilaments. It has been shown that gamma-actin interacting with another costameric protein dystrophin is critical for costameres forming mechanically strong links between the cytoskeleton and the sarcolemmal membrane. Additional studies have shown that gamma-actin colocalizes with alpha-actinin and GFP-labeled gamma actin localized to Z-discs, whereas GFP-alpha-actin localized to pointed ends of thin filaments, indicating that gamma actin specifically localizes to Z-discs in striated muscle cells. During development of myocytes, gamma actin is thought to play a role in the organization and assembly of developing sarcomeres, evidenced in part by its early colocalization with alpha-actinin. Gamma-actin is eventually replaced by sarcomeric alpha-actin isoforms, with low levels of gamma-actin persisting in adult myocytes which associate with Z-disc and costamere domains. Insights into the function of gamma-actin in muscle have come from studies employing transgenesis. In a skeletal muscle-specific knockout of gamma-actin in mice, these animals showed no detectable abnormalities in development; however, knockout mice showed muscle weakness and fiber necrosis, along with decreased isometric twitch force, disrupted intrafibrillar and interfibrillar connections among myocytes, and myopathy.
=== Buffer agents === By buffering any potential pH change, buffer agents can provide chemical stability and ensure the physical compatibility of the topical cream formulation. They ensure that the formulation can deliver the correct amount of drug to the therapeutic application site, is free from microbial contamination, and physically unchanged since the manufacturing day. Nonetheless, buffer agents need to be carefully added to avoid undesirable effects on physical stability. For example, buffer agents may influence the rheological behavior.
He proposed a scenario whereby the critical electrochemistry of enzymatic reactions would have necessitated retention of the specific nucleotide moieties of the original RNA-based enzymes carrying out the reactions, while the remaining structural elements of the enzymes were gradually replaced by protein, until all that remained of the original RNAs were these nucleotide cofactors, "fossils of nucleic acid enzymes".
=== Standard and nonstandard forms === The 20 amino acids that are encoded directly by the codons of the universal genetic code are called standard or canonical amino acids. A modified form of methionine (N-formylmethionine) is often incorporated in place of methionine as the initial amino acid of proteins in bacteria, mitochondria and plastids (including chloroplasts). Other amino acids are called nonstandard or non-canonical. Most of the nonstandard amino acids are also non-proteinogenic (i.e. they cannot be incorporated into proteins during translation), but two of them are proteinogenic, as they can be incorporated translationally into proteins by exploiting information not encoded in the universal genetic code. The two nonstandard proteinogenic amino acids are selenocysteine (present in many non-eukaryotes as well as most eukaryotes, but not coded directly by DNA) and pyrrolysine (found only in some archaea and at least one bacterium). The incorporation of these nonstandard amino acids is rare. For example, 25 human proteins include selenocysteine in their primary structure, and the structurally characterized enzymes (selenoenzymes) employ selenocysteine as the catalytic moiety in their active sites. Pyrrolysine and selenocysteine are encoded via variant codons. For example, selenocysteine is encoded by stop codon and SECIS element. N-formylmethionine (which is often the initial amino acid of proteins in bacteria, mitochondria, and chloroplasts) is generally considered as a form of methionine rather than as a separate proteinogenic amino acid.
Sources: en.wikipedia.org
Measles vaccine is a live attenuated vaccine that protects against becoming infected with measles. Nearly all of those who do not develop immunity after a single dose develop it after a second dose. When the rate of vaccination within a population is greater than 92%, outbreaks of measles typically no longer occur; however, they may occur again if the rate of vaccination decreases. The vaccine's effectiveness lasts many years. It is unclear if it becomes less effective over time. The vaccine may also protect against measles if given within a couple of days after exposure to measles. Measles is a highly contagious viral illness that can lead to serious complications, including pneumonia, acute encephalitis, and, in rare cases, long‑term neurological disease. Pregnant women are at increased risk of severe respiratory complications and adverse pregnancy outcomes such as pregnancy loss and premature birth. The vaccine is generally safe, even for those infected by HIV. Most children do not experience any side effects; those that do occur are usually mild (such as fever, rash, pain at the site of injection, and joint stiffness) and short-lived. Anaphylaxis has been documented in about 3.5–10 cases per million doses. Rates of Guillain–Barré syndrome, autism and inflammatory bowel disease do not appear to be increased by measles vaccination. The vaccine is available both by itself and in combinations such as the MMR vaccine (a combination with the rubella vaccine and mumps vaccine) or the MMRV vaccine (a combination of MMR with the chickenpox vaccine).
We will always have to leave Jaén by Maynas and advance if possible our limits of the coast beyond Tumbes." After noticing, with disgust, the good image that Peru had (above Colombia and Venezuela) in the towns of Guayaquil, Cuenca and Loja in present-day Ecuador, either because the majority of its inhabitants were Quechua-speaking, or because of the proximity they had with the departments of Piura and Cajamarca, with which they had more trade and exchange than with Viceroyalty of New Granada, which was disconnected from the area by natural barriers in the Andes and the Pacific Ocean (arguments given by the Peruvian Francisco María Roca); harming applying the Free Determination of the peoples in their favor (in fact, the annexation of these territories to Gran Colombia would have been done in authoritarian and illegal ways), which would be aggravated by the centralist and authoritarian policies of the Bolivarian government, whose laws generated discontent in the Southern District.
People from different cultures employ a variety of personal cleansing practices after defecation. The anus and buttocks may be either washed with liquids or wiped with toilet paper or other solid materials. In many Muslim, Hindu and Sikh cultures, as well as Southeast Asia and Southern Europe, water is usually used for anal cleansing using a jet, as with a bidet, or most commonly, splashed and washed with the hand. In other cultures (such as many Western countries), cleaning after defecation is generally done with toilet paper only.
In combined mass spectra obtained by summing a large number of individual ion detection events, each peak is a histogram obtained by adding up counts in each individual bin. Because the recording of the individual ion arrival with TDC yields only a single time point, the TDC eliminates the fraction of peak width determined by a limited response time of both the MCP detector and preamplifier. This propagates into better mass resolution. Modern ultra-fast 10 GSample/sec analog-to-digital converters digitize the pulsed ion current from the MCP detector at discrete time intervals (100 picoseconds). Modern 8-bit or 10-bit 10 GHz ADC has much higher dynamic range than the TDC, which allows its usage in MALDI-TOF instruments with its high peak currents. To record fast analog signals from MCP detectors one is required to carefully match the impedance of the detector anode with the input circuitry of the ADC (preamplifier) to minimize the "ringing" effect. Mass resolution in mass spectra recorded with ultra-fast ADC can be improved by using small-pore (2-5 micron) MCP detectors with shorter response times.
Regorafenib is administered orally for the treatment of colorectal cancer, gastrointestinal stromal cancer and hepatocellular carcinoma. Nintedanib is used for the treatment of idiopathic pulmonary fibrosis. Tests for liver function have to be made to modify doses before the therapy can start. Apatinib is used for the treatment of advanced gastric cancer. It is often diagnosed in late stages because there are no early signs or symptoms.
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.
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.