This is a working overview of reverse-phase HPLC, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-27 and is reviewed periodically as new material appears.
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.
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.
| 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 |
One way is to fuse modular binding sites (e.g., MS2 RNA tagging system, or RIDD-RIAD dock-and-lock system) to the phase-separating domain (e.g., synthetic RNA repeat, or IDP) that recruit "solute" or "client" of interest. Such a modular design enables engineering, optimization, and reusability of each fusion molecule, thus commonly applied in synthetic biology and metabolic engineering. Moreover, by applying a relatively slower binding system (e.g., split GFP), the recruitment of target into synthetic condensate can be fine-tuned by growth and division rates of the living cells. Another way to gain temporal control over the formation and dissolution of biomolecular condensates is by using optogenetic tools. Several different systems have been developed which allow for control of condensate formation and dissolution which rely on chimeric protein expression, and light or small molecule activation. In one system, proteins are expressed in a cell which contain light-activated oligomerization domains fused to IDRs. Upon irradiation with a specific wavelength of light, the oligomerization domains bind each other and form a 'core', which also brings multiple IDRs close together because they are fused to the oligomerization domains. The recruitment of multiple IDRs effectively creates a new biopolymer with increased valency. This increased valency allows for the IDRs to form multivalent interactions and trigger LLPS. When the activation light is stopped, the oligomerization domains disassemble, causing the dissolution of the condensate.
=== Research tool === Due to its high proteolytic specificity, thrombin is a valuable biochemical tool. The thrombin cleavage site (Leu-Val-Pro-Arg-Gly-Ser) is commonly included in linker regions of recombinant fusion protein constructs. Following purification of the fusion protein, thrombin can be used to selectively cleave between the arginine and glycine residues of the cleavage site, effectively removing the purification tag from the protein of interest with a high degree of specificity.
Our politics seems more vulnerable to conspiracy theories and outright fabrication." He continued, "Bigotry in any form is blasphemy against the American creed and it means the very identity of our nation depends on the passing of civic ideals to the next generation", while urging citizens to oppose threats to American democracy and be positive role models for young people. The speech was widely interpreted as a denouncement of Donald Trump and his ideologies, despite Bush not mentioning Trump by name. On September 1, 2018, Bush and his wife attended the funeral of John McCain at the Washington National Cathedral in Washington, D.C. where Bush delivered remarks at the service. On November 30, his father died at his home. Shortly before his death, Bush was able to talk with his father on the phone; his father responded with what would be his last words, "I love you too". Bush attended his father's funeral on December 5, delivering a eulogy. In May 2019, on the tenth anniversary of former South Korean president Roh Moo-hyun's death, Bush visited South Korea to pay his respects to Roh, delivering a short eulogy. On June 1, 2020, Bush released a statement addressing the murder of George Floyd and the subsequent nationwide reaction and protests. In the statement, Bush wrote that he and former first lady Laura Bush "are anguished by the brutal suffocation of George Floyd and disturbed by the injustice and fear that suffocate our country".
Through the late 1950s and early 1960s, numerous papers were published on various topics in RNA structure, including RNA-DNA hybridization, triple stranded RNA, and even small-scale crystallography of RNA di-nucleotides—G-C, and A-U—in primitive helix-like arrangements. For a more in-depth review of the early work in RNA structural biology, see the article The Era of RNA Awakening: Structural biology of RNA in the early years by Alexander Rich.
Sources: en.wikipedia.org
=== Angiotensin III === Amino acid sequence: Asp | Arg-Val-Tyr-Ile-His-Pro-Phe Angiotensin III, along with angiotensin II, is considered an active peptide derived from angiotensinogen. It is formed by removing an amino acid from angiotensin II by glutamyl aminopeptidase A, which cleaves the N-terminal Asp residue. Angiotensin III has 40% of the pressor activity of angiotensin II, but 100% of the aldosterone-producing activity. It increases mean arterial pressure. Activation of the AT2 receptor by angiotensin III triggers natriuresis, while AT2 activation via angiotensin II does not. This natriuretic response via angiotensin III occurs when the AT1 receptor is blocked.
On June 22, 2010, Bush said: "While South Korea prospers, the people of North Korea have suffered profoundly," adding that communism had resulted in dire poverty, mass starvation, and brutal suppression. "In recent years," he went on to say, "the suffering has been compounded by the leader who wasted North Korea's precious few resources on personal luxuries and nuclear weapons programs."
== External links == Death Penalty Worldwide, by Cornell Law School – Academic database on every death penalty country in the world Lethalinjection.org, by UC Berkeley School of Law – Web-based information clearinghouse on lethal injection
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 powder is normally held at minus twenty degrees Celsius or below. Light and moisture exposure should be minimized. Repeated warming and cooling cycles are avoided.