A practical reference on drug affinity complex: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-27 and is reviewed periodically as new material appears.
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.
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
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 |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Visual descriptor; not a measure of purity |
| Solubility class | Freely soluble in water | Aqueous dissolution may require gentle mixing |
| Typical storage (powder) | −20 °C or below, desiccated | Protect from light and ambient moisture |
| Typical storage (solution) | 2–8 °C, short term | Freeze aliquots where longer holding is needed |
| Purity assessment | Reversed-phase HPLC, area percent | Values depend on column, gradient, and detection wavelength |
This decrease is almost unnoticeable if a smooth aneurysm is produced in the wall of a capillary by heating and pressurization, as plug flow can be preserved. This invention by Gary Gordon, US Patent 5061361, typically triples the absorbance path length. When used with a UV absorbance detector, the wider cross-section of the analyte in the cell allows for an illuminating beam twice as large, which reduces shot noise by a factor of two. Together these two factors increase the sensitivity of Agilent Technologies's Bubble Cell CE Detector six times over that of one using a straight capillary. This cell and its manufacture are described on page 62 of the June 1995 issue of the Hewlett-Packard Journal.
== Substrate specificity == The phytaspase displays a strict substrate specificity, which resembles that of the animal caspase-3. It recognizes a tetrapetide motive within a target protein and introduces a peptide bond break following an aspartate residue, which is crucial for the hydrolysis. Theoretical speculations, based on a 3D model predictions have been made, pointing to the histidine 331 of the phytaspase peptide chain, that might interact with the Asp in the target peptide and thereby guide the recognition.
As his presidency came to a close, the country experienced a financial crisis, resulting in the Great Recession, prompting his administration and Congress to push through emergency economic measures aimed at stabilizing the financial system, including the Troubled Asset Relief Program. After his second term, Bush returned to Texas, where he has maintained a low public profile. At various points in his presidency, he was both among the most popular and among the least popular presidents in U.S. history. He received the highest recorded approval ratings in the wake of the September 11 attacks, and one of the lowest ratings during the 2008 financial crisis. Bush left office as one of the most unpopular U.S. presidents; however, public opinion of him has improved in his post-presidency. Scholars and historians generally rank Bush as a below-average president.
==== Advantages ==== The biggest advantage of GFP is that it can be heritable, depending on how it was introduced, allowing for continued study of cells and tissues it is expressed in. Visualizing GFP is noninvasive, requiring only illumination with blue light. GFP alone does not interfere with biological processes, but when fused to proteins of interest, careful design of linkers is required to maintain the function of the protein of interest. Moreover, if used with a monomer it is able to diffuse readily throughout cells.
Sources: en.wikipedia.org
=== EC 1.1.4 With a disulfide as acceptor === EC 1.1.4.1: Now EC 1.17.4.4, vitamin-K-epoxide reductase (warfarin-sensitive) EC 1.1.4.2: Now EC 1.17.4.5, vitamin-K-epoxide reductase (warfarin-insensitive)
The public consortium also bought one of the PE Biosystems 3700 sequencers, and had plans to buy 200 more. The machine proved to be so fast that by late March 1999 the consortium announced that it had revised its timeline, and would release by the Spring of 2000 a "first draft sequence" for 80% of the human genome. At year end 1998, the PE Biosystems Group's sales reached US$940 million.
Windtree Therapeutics, Inc. (formerly Discovery Laboratories) is an American company which was set up in 1992 and now is based in Warrington, Pennsylvania, developing drug products (pulmonary medicine) for patients with respiratory disease. The company joined an alliance with Laboratorios del Dr. Esteve, S.A. In 2016, Discovery Laboratories changed name to Windtree Therapeutics, Inc.
Sources: en.wikipedia.org
Cool, dark, and dry conditions are standard, with storage at minus twenty degrees Celsius or below. Desiccant and sealed vials limit moisture uptake. Repeated warming and cooling of the container is generally avoided.
There is no single agreed limit, and laboratory practice varies widely. Refrigeration slows degradation, and freezing aliquots is often described for longer holding. Any visible cloudiness or precipitate indicates the solution should be discarded.
Mass spectrometry provides the most direct confirmation through molecular mass. Reversed-phase chromatography supports purity assessment, and peptide mapping or amino acid analysis can corroborate sequence. No single method establishes both purity and identity on its own.
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.