If you have been reading about copper tripeptide 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.
Updated 2025-09-23. Numbers and descriptions here follow the published literature rather than marketing material.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide backbone consists of glycine, histidine, and lysine joined in that order. Copper is held through the imidazole nitrogen of histidine and the alpha-amino group at the N-terminus, which together produce a square-planar arrangement around the metal center. The solid appears blue to violet, a color that originates from d-d electronic transitions within the copper coordination sphere. The complex is indexed under CAS number 89030-95-5.
The sequence now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
Solid GHK-Cu appears as a blue to blue-violet powder, and the colour is a direct consequence of copper coordination. The complex dissolves readily in water and in many polar solvents, while the free peptide behaves differently. Solubility in nonpolar media is low, which limits its use in oil-based systems. Solutions are typically prepared fresh because the dissolved form is more exposed to hydrolysis and to loss of the metal ion than the dry powder. Working concentrations are usually low, and preparation notes often specify the solvent and the order of addition.
Dry material is typically held at low temperature, often around minus twenty degrees Celsius, and protected from moisture and light. Copper complexes can release their metal ion under acidic conditions or in the presence of competing chelators. Hydrolysis of the peptide backbone is a slower but real pathway, and the histidine residue is susceptible to oxidation over long periods. Stability statements therefore depend on formulation, pH, and container, and they should be read as conditional rather than absolute.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) peptide complex | Peptide chain coordinated to a single metal ion |
| CAS number | 89030-95-5 | Indexed for the peptide-copper complex |
| Molecular formula | C14H22CuN6O4 | Approximate formula for a one-to-one complex |
| Appearance | Blue to violet solid | Color from copper d-d transitions |
| Solubility class | Freely soluble in water | Also dispersible in some polar solvents |
The compound was first isolated from human plasma by the biochemist Loren Pickart in 1973. Early work identified it as a factor that altered the behavior of cultured liver cells, and later studies linked it to connective tissue and wound-related processes. Reported plasma concentrations fall markedly between roughly age twenty and age sixty, a pattern that generated interest in copper peptide biology. Whether that decline has functional consequences remains an open question, because differences observed across age groups do not by themselves establish causation. Research interest later expanded into cosmetic and tissue-culture settings.
Mechanistic accounts focus on how the complex delivers copper and how the released peptide interacts with the extracellular matrix. Copper is an essential cofactor for lysyl oxidase and other enzymes involved in collagen and elastin cross-linking, and GHK is one of several peptides able to carry the metal. Reported effects include altered gene expression in fibroblasts and changes in matrix metalloproteinase activity, although many of these findings come from cell culture rather than whole organisms. The relative contribution of the peptide backbone, the copper ion, and downstream copper metabolism is not fully resolved.
Analytical verification commonly relies on high-performance liquid chromatography for purity assessment and mass spectrometry for identity confirmation. Spectroscopic methods such as UV-visible absorption and electron paramagnetic resonance can probe the metal centre itself, since the d9 configuration of copper(II) produces characteristic signals. Elemental analysis or plasma-based techniques quantify copper content. Because each method reports a different aspect of the same sample, purity figures are most meaningful when the technique and its detection wavelength are stated alongside the value.
Stability of the complex in solution depends on pH, temperature, and the presence of competing ligands. It is generally described as more resistant to breakdown than the metal-free chain, since coordination reduces susceptibility to enzymatic attack. Oxidation and hydrolysis can nevertheless proceed over time in aqueous media. Storage guidance in laboratory settings commonly involves refrigeration, protection from light, and avoidance of strongly alkaline conditions. Published data on long-term behaviour vary considerably and depend on the specific matrix.
Handling practices for the solid material emphasise low temperature and dryness. The lyophilised or powdered form is typically kept at refrigerator or freezer temperatures together with a desiccant. Working solutions are often prepared fresh, because repeated freeze-thaw cycles and extended storage may alter the complex. Glass or inert plastic containers are preferred over materials that could leach metal ions into the preparation. Such practices follow general peptide conventions rather than substance-specific regulations.
The situation in which a treatment contrast (e.g. difference between investigational product and control) is dependent on another factor (e.g. centre). A quantitative interaction refers to the case where the magnitude of the contrast differs at the different levels of the factor, whereas for a qualitative interaction the direction of the contrast differs for at least one level of the factor. (ICH E9) Inter-rater reliability
An apparent attempt by a soldier in Baghdad to force a detainee to hold a gun to create the appearance of a justifiable homicide. Two mock executions of Iraqi juveniles by Army personnel (documents obtained by the ACLU two weeks ago showed that U.S. Marines had also conducted a mock execution of juvenile detainees). Allegations of a competition among Army dog handlers at Abu Ghraib prison to see who could make Iraqi detainees urinate themselves the fastest. The use of death threats during interrogations. Command failures in providing appropriate training to military interrogators in Baghdad detention facilities.
=== Feature films === Phang's debut feature film that she directed and wrote was entitled Half-Life (2008) and it starred Sanoe Lake, Julia Nickson-Soul, Leonardo Nam, James Eckhouse, Susan Ruttan and Alexander Agate. The film premiered at the 2008 Sundance Film Festival in the New Frontiers section, and also screened at the Gen Art Film Festival (where it won a Best Feature award), the San Francisco International Asian American Film Festival (where it won a Best Narrative award), the Asian American International Film Festival (where Phang won the "Emerging Director Award"), the Fairy Tales International Gay & Lesbian Film Festival (where it won the Visionary Award), the Tokyo International Film Festival (where it was in-competition and was nominated for the Tokyo Grand Prix), the Mannheim-Heidelberg International Film Festival (where it was also in competition and nominated for the Main Award), and the International Women's Film Festival in Seoul, Korea (where it was opening night film). The film received a limited theatrical release on December 1, 2009. After Half life, Phang's follow-up project was, Look For Water, and Crazy Beats Strong Every Time. Phang received a grant from the Sundance Institute Cinereach Grant, the Sundance Annenberg Feature Film Fellowship, and the Tribeca Film Festival to support these developments. Phang's follow up film that she directed, wrote and edited was Advantageous (2015), which was based on her award-winning short film of the same name. The film starred Jacqueline Kim, Ken Jeong, James Urbaniak, Freya Adams and Samantha Kim.
Sources: en.wikipedia.org
Having personally experienced a confused night action off Guadalcanal, Lee was not enthusiastic about a night engagement with Japanese surface forces, believing that his crews were not adequately trained for it. Shortly after learning Lee's opinion, Mitscher requested permission from Spruance to move TF 58 west during the night, to reach a launch position at dawn that would allow for a maximum aerial assault on the enemy force. Spruance considered for an hour, then refused Mitscher's request. Mitscher's staff was disappointed with Spruance's decision. Burke later commented: "We knew we were going to have hell slugged out of us in the morning. We knew we couldn't reach them. We knew they could reach us." Spruance's decision was influenced by his orders from Nimitz, who had made it clear that the protection of the invasion fleet was the primary mission of TF 58. Spruance had concerns that the Japanese would attempt to draw his main fleet away from the Marianas with a diversionary force while slipping an attack force in to destroy the landing fleet. Locating and destroying the Japanese fleet was not his primary objective, and he was unwilling to allow the main strike force of the Pacific Fleet to be drawn westward, away from the amphibious forces. Mitscher accepted the decision without comment. Spruance's decision in this matter, although subsequently criticized, was certainly justified; by this point in the war, it was well known that Japanese operational plans frequently relied on the use of decoys and diversionary forces.
=== Frequency multiplier === In 2009, researchers built experimental graphene frequency multipliers that take an incoming signal of a certain frequency and output a signal at a multiple of that frequency.
According to Adorno's translator Robert Hullot-Kentor, the central motive of Adorno's work thus consists in determining "how life could be more than the struggle for self-preservation." In this sense, the principle of self-preservation, Adorno writes in Negative Dialectics, is nothing but "the law of doom thus far obeyed by history." At its most basic, Adorno's thought is motivated by a fundamental critique of this law. Adorno was chiefly influenced by Max Weber's critique of disenchantment, György Lukács's Hegelian interpretation of Marxism, and Walter Benjamin's philosophy of history. Adorno, along with the other major Frankfurt School theorists, Max Horkheimer and Herbert Marcuse, argued that advanced capitalism had managed to contain or liquidate the forces that would bring about its collapse and that the revolutionary moment, when it would have been possible to transform it into socialism, had passed. As he put it at the beginning of his Negative Dialectics (1966), philosophy is still necessary because the time to realize it has been missed. Adorno argued that capitalism had become more entrenched by attacking the objective basis of revolutionary consciousness and liquidating the individualism that had underpinned critical consciousness. Adorno, as well as Horkheimer, critiqued all forms of positivism as responsible for technocracy and disenchantment and sought to produce a theory that both rejected positivism and avoided reinstating traditional metaphysics.
== History == As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxidants such as ascorbic acid (vitamin C), polyphenols, and tocopherols. The evolution of angiosperm plants between 50 and 200 million years ago resulted in the development of many antioxidant pigments – particularly during the Jurassic period – as chemical defences against reactive oxygen species (ROS) that are byproducts of photosynthesis. Originally, the term antioxidant specifically referred to a chemical that prevented the consumption of oxygen. In the late 19th and early 20th centuries, extensive study concentrated on the use of antioxidants in important industrial processes, such as the prevention of metal corrosion, the vulcanization of rubber, and the polymerization of fuels in the fouling of internal combustion engines. Early research on the role of antioxidants in biology focused on their use in preventing the oxidation of unsaturated fats, which is the cause of rancidity. Antioxidant activity could be measured simply by placing the fat in a closed container with oxygen and measuring the rate of oxygen consumption. However, it was the identification of vitamins C and E as antioxidants that revolutionized the field and led to the realization of the importance of antioxidants in the biochemistry of living organisms. The possible mechanisms of action of antioxidants were first explored when it was recognized that a substance with anti-oxidative activity is likely to be one that is itself readily oxidized.
Sources: en.wikipedia.org
Some raids were met with 100% of the fighters dispatched successfully engaging their targets, while German aircraft returned home over half the time never having seen the enemy. It is for this reason that Churchill credits Chain Home with winning the Battle.
=== Early developments === The first cold breakfast cereal, Granula, was invented in the United States in 1863 by James Caleb Jackson, operator of Our Home on the Hillside which was later replaced by the Jackson Sanatorium in Dansville, New York. The cereal never became popular, due to the inconvenient necessity of tenderizing the heavy bran and graham nuggets by soaking them overnight. George H. Hoyt created Wheatena circa 1879, during an era when retailers would typically buy cereal (the most popular being cracked wheat, oatmeal, and cerealine) in barrel lots, and scoop it out to sell by the pound to customers. Hoyt, who had found a distinctive process of preparing wheat for cereal, sold his cereal in boxes, offering consumers a more sanitary and consumer-friendly option.
In June 2025, protests broke out in Los Angeles after a series of federal immigration raids. As demonstrations continued, President Trump issued a memorandum federalizing up to 4,000 California National Guard troops and deploying U.S. Marines to assist with the response. Newsom objected, calling it an unconstitutional overreach of federal authority. On June 9, the State of California, led by Newsom, filed a federal lawsuit, Newsom v. Trump, challenging the legality of the troop deployment. The complaint argued that the order exceeded the president's statutory powers under 10 U.S.C. § 252 and violated the Tenth Amendment and the Posse Comitatus Act. In April 2025, Newsom called the illegal deportation of Kilmar Abrego Garcia to El Salvador "the distraction of the day" set up by the Trump administration. U.S. Senator Chris Van Hollen criticized Newsom's comment, saying, "I think Americans are tired of elected officials or politicians who are all finger to the wind. Anyone who can't stand up for the Constitution and the right of due process doesn't deserve to lead."
Mitogen-activated protein kinase 3 (MAPK3) is also known as extracellular signal-regulated kinase 1 (ERK1). Transgenic gene knockout mice lacking MAPK3 are viable and it is thought that MAPK1 can fulfill some MAPK3 functions in most cells. The main exception is in T cells. Mice lacking MAPK3 have reduced T cell development past the CD4+ and CD8+ stage.
== External links == Finding Aid to The Dr. Michael Somogyi Collection, 1912–1979 (bulk 1924–1970) at the Science History Institute (For full finding aid, click on 'Dr. Michael Somogyi Collection Finding Aid'.) Finding Aid to Photographs from the Dr. Michael Somogyi Collection, 1912–1971 (bulk 1950s) at the Science History Institute (For full finding aid, click on 'Dr. Michael Somogyi Collection Finding Aid'.)
Sources: en.wikipedia.org
It is the copper complex of the tripeptide glycyl-L-histidyl-lysine. The metal ion is held by the histidine imidazole group and the peptide N-terminus. Most research on it concerns skin and wound models.
The tripeptide was first isolated from human plasma and has also been reported in saliva and urine. Plasma levels appear to decline with age in some small studies. Those observations rest on limited sample sizes.
It is not authorized as a systemic medicine in most countries. Cosmetic preparations list it as an ingredient rather than an active pharmaceutical substance. Legal status therefore differs by jurisdiction.
The colour comes from electronic transitions in the coordinated copper(II) ion. Ligand field effects absorb part of the visible spectrum. A colourless or greenish sample may indicate degraded material.