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Structure And Receptor Pharmacology — Deep Dive

By Editorial Desk · published 2026-03-27 · last reviewed 2026-05-15 · News

modified GRF(1-29) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-05-15. Anything still debated is marked as such rather than presented as settled.

Structure And Receptor Pharmacology

Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.

Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.

CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.

Analytical Characterization and Storage

Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.

Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.

Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.

Cjc-1295 at a glance

PropertyValueNotes
Peptide classSynthetic GHRH analogueBuilt on a 29 residue sequence
Primary targetGHRH receptor (GHRHR)Class B G protein coupled receptor
Unconjugated half lifeMinutesLimited by protease degradation
Key modificationFour residue substitutionsPositions 2, 8, 15 and 27
Common synonymModified GRF(1-29)Usually denotes the form without DAC

Background and Molecular Design

The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.

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Compound Identity and Development History

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.

CJC-1295 Structure And Mechanism

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.

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.

Supporting material

==== Economy ==== According to Tel Aviv University economist Tomer Fadlon, there would be long-term and significant effects on northern Israel's economy if its population did not return. He further said that even if Israel achieved victory in Gaza, the north would possibly not see an economic recovery. The conflict severely hurt the tourism industry in the north, which employs many people. Many factories in the region have not shut down but suffered labor shortages of up to 50%. According to an estimate by the Bank of Israel in November 2023, the Israeli economy suffers the loss of 590 million shekels ($158 million) every week due absence of work caused by the evacuation of 144,000 people after the Gaza war, 40% of them from the north. Once-robust communities such as Snir and Kiryat Shmona were mostly emptied following the evacuation orders in northern Israel. Kiryat Shmona was planned to be used by food technology businesses, but companies left following the city's evacuation in October 2023. Northern Israel has one-third of Israel's agricultural land, and the occupied Golan Heights and Galilee accounted for 73% of Israel's annual egg production; however, after the outbreak of the conflict, few people remained in the north to tend chicken coops, resulting in a decline in domestic egg production. In August 2024, the Ministry of Agriculture and Food Security approved a quota for the import of 45 million eggs due to the anticipated drop in local production over the conflict and other reasons.

Feoktist I. Bogoyavlenskiy (1933–1935) Vasiliy V. Evlampiev (1935–1939) Faizi F. Faizyllin (1958–1960) Boris A. Arbuzov (1941–1950) Arkadiy N. Pudovik (1950–1958) Faizi F. Faizyllin (1958–1960) Vera F. Toropova (1960–1965) Alexander I. Kostromin (1965–1968) Alexander I. Konovalov (1968–1972) Irina V. Konovalova (1972–1987) Galina A. Chmutova (1987–1992) Nikolai A. Ulakhovich (1992–2000) Vladimir I. Galkin (since 2000– until present) Department of Analytical Chemistry Department of High Molecular and Organoelement Compounds Department of Inorganic Chemistry Department of Organic Chemistry Department of Physical Chemistry Department of Chemical Education Department of Environmental Chemistry Department of Applied Chemistry Department of Stereochemistry Division for Analytical Chemistry Division for Inorganic Chemistry and Coordination chemistry Division for Organic Chemistry Division for Physical Chemistry Division for Organoelement Compounds Division for Stereochemistry Division for Applied Chemistry Division for Environmental Chemistry

Uranium (92U) is a naturally occurring radioactive element (radioelement) with no stable isotopes. It has two primordial isotopes, uranium-238 and uranium-235, that have long half-lives and are found in appreciable quantity in Earth's crust. The decay product uranium-234 is also found. Other isotopes such as uranium-233 have been produced in breeder reactors. In addition to isotopes found in nature or nuclear reactors, many isotopes with far shorter half-lives have been produced, ranging from 214U to 242U (except for 220U). The standard atomic weight of natural uranium is 238.02891(3). Natural uranium consists of three main isotopes, 238U (99.2739–99.2752% natural abundance), 235U (0.7198–0.7202%), and 234U (0.0050–0.0059%). All three isotopes are radioactive (i.e., they are radioisotopes), and the most abundant and stable is uranium-238, with a half-life of 4.463×109 years (about the age of the Earth). Uranium-238 is an alpha emitter, decaying through the 18-member uranium series into lead-206. The decay series of uranium-235 (historically called actino-uranium) has 15 members and ends in lead-207. The constant rates of decay in these series makes comparison of the ratios of parent-to-daughter elements useful in radiometric dating. Uranium-233 is made from thorium-232 by neutron bombardment.

=== Recommendations === The IEEE standard 1188–1996 recommends replacing lithium-ion batteries in an electric vehicle, when their charge capacity drops to 80% of the nominal value. In what follows, we shall use the 20% capacity loss as a comparison point between different studies. We shall note, nevertheless, that the linear model of degradation (the constant % of charge loss per cycle or per calendar time) is not always applicable, and that a "knee point", observed as a change of the slope, and related to the change of the main degradation mechanism, is often observed.

White Rhodesian officers and non-commissioned officers left the colony in September and October 1939 to command units of black Africans in the west and east of the continent, with most joining the Royal West African Frontier Force (RWAFF) in the Colony of Nigeria, the Gold Coast and neighbouring colonies. The deployment of white Rhodesian officers and NCOs to command black troops from elsewhere in Africa met with favour from the military leadership and became very prevalent.

Sources: en.wikipedia.org

Notes from published material

The three substrates of this enzyme are D-erythrose 4-phosphate, oxidised nicotinamide adenine dinucleotide (NAD+), and water. Its products are 4-phospho-D-erythronic acid, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is D-erythrose 4-phosphate:NAD+ oxidoreductase. Other names in common use include erythrose 4-phosphate dehydrogenase, E4PDH, GapB, Epd dehydrogenase, and E4P dehydrogenase. This enzyme participates in vitamin B6 metabolism (see DXP-dependent biosynthesis of pyridoxal phosphate).

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Bilawal Bhutto Zardari (born 21 September 1988) is a Pakistani politician who served as the 37th Minister of Foreign Affairs from 2022 to 2023. He became the chairman of the Pakistan People's Party in 2007 following his mother's assassination. Born in Karachi, Sindh, Bilawal maternally belongs to the Bhutto family and paternally to the Zardari family, he is the son of former Prime Minister Benazir Bhutto and President Asif Ali Zardari, and the grandson of former President Zulfikar Ali Bhutto. Bilawal Zardari was a member of the National Assembly of Pakistan from 2018 to 2023. He was re-elected as a Member of the National Assembly of Pakistan in the 2024 Pakistani general election from newly formed constituency NA-194 Larkana-I, taking oath in 2024.

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Sources: en.wikipedia.org

Frequently asked questions

Is CJC-1295 the same as modified GRF(1-29)?

The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.

What does the acronym DAC refer to?

DAC stands for drug affinity complex, a term describing the maleimidopropionic acid linker. This group forms a covalent bond with the cysteine residue on serum albumin after administration. The resulting adduct is what extends the circulating half life from minutes to days.

Does this peptide occur naturally in the body?

No. It is entirely synthetic and does not correspond to any known endogenous peptide. The design starts from human growth hormone releasing hormone and introduces deliberate substitutions. Any biological effect comes from mimicking the natural hormone at its receptor.

How is sample identity confirmed?

Mass spectrometry establishes whether the observed molecular weight matches the calculated sequence mass. Chromatographic retention and fragment mapping add further confidence about sequence and composition. A single technique alone is rarely treated as sufficient evidence of identity.

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