The short version of drug affinity complex fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-12. Anything still debated is marked as such rather than presented as settled.
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.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
| 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 |
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
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.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.
Serum, suspected to contain IgE antibodies, is drawn from the allergic (atopic) patient. This serum is injected intradermally into a non-allergic person. The suspected antigens are then intradermally injected into the non-allergic person 24–48 hours later. If the person being tested for an allergy has made antibodies for the antigen, this will cause a local reaction in the non-allergic person when the antibodies mix with the antigen. This demonstrates a type I hypersensitivity reaction, and the allergic reaction to the injected antigen is confirmed for the patient being tested. A positive PK test usually appears as a wheal and flare. The test was developed by Otto Prausnitz and Heinz Küstner. The first PK test occurred in 1921 when Prausnitz injected Küstner's serum into his abdominal skin. Küstner had previously noted that he developed allergic symptoms after eating fish. After eating some fish, Prausnitz's skin became hot, red, and swollen at the site of the serum injection, confirming their hypothesis that Küstner was allergic to fish.
== Personal life and death == French met Patricia Anne "Pat" Soule while attending Pasadena City College, and the two married in June 1950. They were married for 66 years, until her death in February 2017, and had two children. Pat worked as an acting teacher at Bellevue College and later worked with her husband on Imagination Theatre. French died in Seattle on December 20, 2017, at age 89.
== Toxicity == Buformin was withdrawn from the market in many countries due to an elevated risk of causing lactic acidosis (although not the US, where it was never sold). Buformin is still available and prescribed in Romania (timed release Silubin Retard is sold by Zentiva), Hungary, Taiwan and Japan (sold by Nichi-Iko Pharmaceutical Co., Ltd as "DIBETOS" tablets, each containing 50 mg buformin hydrochloride). The lactic acidosis occurred only in patients with a buformin plasma level of greater than 0.60 μg/mL and was rare in patients with normal renal function. In one report, the toxic oral dose was 329 ± 30 mg/day in 24 patients who developed lactic acidosis on buformin. Another group of 24 patients on 258 ± 25 mg/day did not develop lactic acidosis on buformin.
== Putative SLCs == Putative SLCs, also called atypical SLCs, are novel, plausible secondary active or facilitative transporter proteins that share ancestral background with the known SLCs. The atypical SLCs of MFS type can, however, be subdivided into 15 Putative MFS Transporter Families (AMTF). All the putative SLCs are plausible SLC transporters. Some are only "atypical" when it comes to their nomenclature; the genes have an SLC assignment but as an alias, and have retained their already assigned "non-SLC" gene symbol as the approved symbol. Here are some Putative SLCs listed: OCA2, CLN3, TMEM104, SPNS1, SPNS2, SPNS3, SV2A, SV2B, SV2C, SVOP, SVOPL, MFSD1, MFSD2A, MFSD2B, MFSD3, MFSD4A, MFSD4B, MFSD5, MFSD6, MFSD6L, MFSD8, MFSD9, MFSD10, MFSD11, MFSD12, MFSD13A, MFSD14A, MFSD14B, UNC93A and UNC93B1.
Sources: en.wikipedia.org
create eicosanoids hormones act on thermoregulatory center of hypothalamus to produce fever increase mating behaviors in goldfish cause the uterus to contract and/or to relax prevent gastrointestinal tract from self-digesting, contributing to its mucosal defence in multifactorial way.
The Campaign for Safe Cosmetics has also highlighted concerns. Numerous studies have revealed that hydroquinone, if taken orally, can cause exogenous ochronosis, a disfiguring disease in which blue-black pigments are deposited onto the skin; however, skin preparations containing the ingredient are administered topically. The FDA had classified hydroquinone in 1982 as a safe product—generally recognized as safe and effective (GRASE). Additional studies under the National Toxicology Program (NTP) were suggested to determine whether there is a risk to humans from the use of hydroquinone. NTP evaluation showed some evidence of long-term carcinogenic and genotoxic effects. While hydroquinone remains widely prescribed for treatment of hyperpigmentation, questions raised about its safety profile by regulatory agencies in the EU, Japan, and the USA encourage the search for other agents with comparable efficacy. Several such agents are already available or under research, including azelaic acid, kojic acid, retinoids, cysteamine, topical steroids, glycolic acid, and other substances. One of these, 4-butylresorcinol, has been proven to be more effective at treating melanin-related skin disorders by a wide margin, as well as safe enough to be made available over the counter. In the anthraquinone process, substituted hydroquinones, typically anthrahydroquinone, are used to produce hydrogen peroxide, which forms spontaneously on reaction with oxygen. The type of substituted hydroquinone is selected depending on reactivity and recyclability.
Deep sea communities around Japan are mainly researched by Japan Agency for Marine-Earth Science and Technology (JAMSTEC). DSV Shinkai 6500, Kaikō, and other groups have discovered many sites. Methane seep communities in Japan are distributed along plate convergence areas because of the accompanying tectonic activity. Many seeps have been found in the Japan Trench, Nankai Trough, Ryukyu Trench, Sagami Bay, Suruga Bay, and the Sea of Japan. Members of cold seep communities are similar to other regions in terms of family or genus, such as Polycheata, Lamellibrachia, Bivalavia, Solemyidae, Bathymodiolus in Mytilidae, Thyasiridae, Calyptogena in Vesicomyidae, and so forth. Many of the species in Japan's cold seeps are endemic. In Kagoshima Bay, there are methane gas seepages called "tagiri" (boiling). Lamellibrachia satsuma live around there. The depth of this site is only 80 m, which is the shallowest point where Siboglinidae are known to live. L. satsuma may be kept in an aquarium for a long period at 1 atm. Two aquariums in Japan are keeping and displaying L. satsuma. An observation method to introduce it into a transparent vinyl tube is being developed.
Sources: en.wikipedia.org
Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a catalyst in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from ultraviolet radiation (UV). The semiconductor properties of zinc oxide make it useful in varistors and photocopying products. The zinc zinc-oxide cycle is a two step thermochemical process based on zinc and zinc oxide for hydrogen production. Zinc chloride is often added to lumber as a fire retardant and sometimes as a wood preservative. It is used in the manufacture of other chemicals. Zinc methyl (Zn(CH3)2) is used in a number of organic syntheses. Zinc sulfide (ZnS) is used in luminescent pigments such as on the hands of clocks, X-ray and television screens, and luminous paints. Crystals of ZnS are used in lasers that operate in the mid-infrared part of the spectrum. Zinc sulfate is a chemical in dyes and pigments. Zinc pyrithione is used in antifouling paints. Zinc powder is sometimes used as a propellant in model rockets. When a compressed mixture of 70% zinc and 30% sulfur powder is ignited there is a violent chemical reaction. This produces zinc sulfide, together with large amounts of hot gas, heat, and light.
== Naval career == Upon his graduation from Tufts, Bello was commissioned an ensign in the United States Navy and served a four-year tour that included a tour of duty in South Vietnam as supply officer for PBR Mobile Base II on the Mekong Delta with a mission of combat support for several Patrol Boat, River (PBR) squadrons. He was awarded the Navy Commendation Medal with Combat V for meritorious service. In 1972, after Vietnam, Bello was assigned to the Moffett Field Naval Air Station Moffett Field as the Navy Exchange Officer. He resigned his commission as a Lieutenant to attend graduate school.
===== Sclerenchyma ===== Sclerenchyma (Greek, Sclerous means hard; enchyma means infusion) consists of thick-walled, dead cells and protoplasm is negligible. These cells have hard and extremely thick secondary walls due to uniform distribution and high secretion of lignin and have a function of providing mechanical support. They do not have inter-cellular spaces between them. Lignin deposition is so thick that the cell walls become stronger, rigid and impermeable to water, which are also known as a stone cells or sclereids. These tissues are mainly of two types: sclerenchyma fiber and sclereids. Sclerenchyma fiber cells have a narrow lumen and are long, narrow and unicellular. Fibers are elongated cells that are strong and flexible, often used in ropes. Sclereids have extremely thick cell walls and are brittle, and are found in nutshells and legumes.
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.
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.