The short version of IGF-1 fits in a sentence. The long version — which is the one that helps — is below.
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The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
Reports on this compound commonly follow serum growth hormone and insulin-like growth factor 1 across defined time windows. Protocols differ in sampling frequency, assay platform, and participant characteristics, which makes direct comparison between publications difficult. Some work focuses on pulsatile release patterns instead of average concentrations. Whether repeated exposure alters endogenous hormone rhythms over long periods remains an open question, and the formal literature is thinner than the volume of informal commentary implies.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
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.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
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.
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.
=== Conformational analysis === One of the primary methods for evaluating chemical stability and energetics is conformational analysis. Physical organic chemists use conformational analysis to evaluate the various types of strain present in a molecule to predict reaction products. Strain can be found in both acyclic and cyclic molecules, manifesting itself in diverse systems as torsional strain, allylic strain, ring strain, and syn-pentane strain. A-values provide a quantitative basis for predicting the conformation of a substituted cyclohexane, an important class of cyclic organic compounds whose reactivity is strongly guided by conformational effects. The A-value is the difference in the Gibbs' free energy between the axial and equatorial forms of substituted cyclohexane, and by adding together the A-values of various substituents it is possible to quantitatively predict the preferred conformation of a cyclohexane derivative. In addition to molecular stability, conformational analysis is used to predict reaction products. One commonly cited example of the use of conformational analysis is a bi-molecular elimination reaction (E2). This reaction proceeds most readily when the nucleophile attacks the species that is antiperiplanar to the leaving group. A molecular orbital analysis of this phenomenon suggest that this conformation provides the best overlap between the electrons in the R-H σ bonding orbital that is undergoing nucleophilic attack and the empty σ* antibonding orbital of the R-X bond that is being broken.
=== Pharmacodynamics === Romergoline shows high affinity for the dopamine D2 receptor (Ki = 6.5 nM), α2-adrenergic receptor (Ki = 4.0 nM), and serotonin 5-HT1A receptor (Ki = 4.0 nM). It also possesses moderate (submicromolar) affinity for the dopamine D1 receptor (Ki = 55 nM) and ketanserin-labeled serotonin 5-HT2 receptor (Ki = 24 nM). Conversely, the drug shows slight or negligible affinity for the α1-adrenergic receptor (Ki = 113 nM), muscarinic acetylcholine receptors (Ki = >10,000 nM), and sigma receptors (Ki = >10,000 nM). Romergoline is said to act as both a dopamine receptor agonist and antagonist, depending on the circumstances. More specifically, the drug is said to act as a D2 receptor silent antagonist under normal dopamine-replete circumstances, but in a dopamine-depleted state, it acts as a powerful dopamine D1 receptor full agonist. This transformation of the drug's activity is thought to be due to development of dopamine D1 receptor supersensitivity with dopamine depletion. Romergoline produces hypolocomotion in rodents and monkeys, inhibits apomorphine-induced climbing behavior in rodents, causes antiemetic effects in dogs, strongly increases prolactin levels in rodents, and antagonizes amphetamine-induced toxicity in rodents. With dopamine depletion however, romergoline induces hyperlocomotion and contralateral turning behavior in 6-hydroxydopamine-lesioned rodents, reverses MPTP-induced akinesia and parkinsonism in monkeys, and reverses reserpine-induced hypokinesia.
7 July The first tandem perovskite-silicon solar cell to exceed 30% efficiency (31.25%) is independently certified by the National Renewable Energy Laboratory. A study into the effects of a global nuclear war on the world's oceans is published, revealing a rapid 10.5 °C (18.9 °F) drop in temperature, along with many longer-lasting impacts. 8 July – Astronomers report the discovery of massive amounts of prebiotic molecules, including precursors for RNA, in the Galactic Center of the Milky Way Galaxy. 9 July – Researchers report the development of an efficient, secure and convenient method to separate, purify, store and transport large amounts of hydrogen for energy storage in renewables-based energy systems as powder using ball milling. 11 July Researchers report the development of a deep learning system that learns intuitive physics from visual data (of virtual 3D environments) to some degree "from scratch" based on an unpublished approach inspired by studies of visual cognition in infants. On 25 July, other researchers report the development of a machine learning algorithm that could discover sets of basic variables of various physical systems and predict the systems' future dynamics from video recordings of their behavior. News outlets report about the development of algae biopanels by a company for sustainable energy generation with unclear viability after other researchers built the self-powered BIQ house prototype in 2013.
Sources: en.wikipedia.org
2011 Sir Alec John Jeffreys: Developed techniques for DNA fingerprinting and DNA profiling 2010 Pat Brown: Pioneering work in the development of microarrays, and the diverse applications of this technology in genetic research. 2009 Mathias Uhlén 2008 Ruedi Aebersold 2007 Donald F. Hunt 2006 Roger Tsien 2005 Stephen Fodor 2004 Edwin Southern 2003 Franz Hillenkamp and Michael Karas 2002 John Fenn 2001 Csaba Horvath 2000 Leroy Hood 1999 Marvin H. Caruthers for pioneering contributions to the chemical synthesis of DNA and RNA 1998 Bruce Merrifield 1997 Lloyd M. Smith 1996 David Lipman 1995 Klaus Biemann 1994 Frederick Sanger
Cortisol is synthesized from cholesterol. Synthesis takes place in the zona fasciculata of an adrenal cortex. The name "cortisol" is derived from the word 'cortex'. Cortex means "the outer layer"—a reference to the adrenal cortex, the part of the adrenal gland where cortisol is produced. While the adrenal cortex in humans also produces aldosterone in the zona glomerulosa and some sex hormones in the zona reticularis, cortisol is its main secretion in humans and several other species. In cattle, corticosterone levels may approach or exceed cortisol levels. In humans, the medulla of the adrenal gland lies under its cortex, mainly secreting the catecholamines adrenaline (epinephrine) and noradrenaline (norepinephrine) under sympathetic stimulation. Synthesis of cortisol in the adrenal gland is stimulated by the anterior lobe of the pituitary gland with ACTH; ACTH production is, in turn, stimulated by CRH, which is released by the hypothalamus. ACTH increases the concentration of cholesterol in the inner mitochondrial membrane, via regulation of the steroidogenic acute regulatory protein. It also stimulates the main rate-limiting step in cortisol synthesis, in which cholesterol is converted to pregnenolone and catalyzed by cytochrome P450SCC (side-chain cleavage enzyme).
== Cause == Aside from L. odoratus, other members of the genus are also known to cause the disease, including L. sylvestris, L. cicera, and L. clymenum. L. odoratus grows well under famine conditions, often severe drought, where it is cultivated. These legumes carry a variety of osteolathyrogenic compounds, specifically excitatory amino-compounds. The most widely studied of these compounds is beta-aminopropionitrile (BAPN), which exerts its deleterious effect by an unknown yet potently irreversible mechanism. Other instigators are ureides, semicarbazides and thiosemicarbazides, which are believed to chelate the prosthetic Cu(II)-bipyridine cofactor complex in the enzyme lysyl oxidase. Lysyl oxidase is an important enzyme for the creation of crosslinks between collagen triple-helices in connective tissue. By oxidizing the terminal amino group of lysine, an aldehyde is created. This aldehyde can undergo several reactions with neighboring aldehydes or amines to create strong covalent cross-links between collagen tertiary structures in bone and cartilage. The main product of these reactions is the aldimine compound dehydrohydroxylysinonorleucine. This unique crosslink can be formed by the Schiff base mechanism in which the lone pair of electrons on a primary amine react with the carbonyl carbon of an aldehyde. Other crosslinks include the formation of an α,β-unsaturated ketone via aldol condensation and hydroxylysinonorleucine. If these crosslinks are not formed, as in the case of osteolathyrism, the synthesis of strong mesenchymal and mesodermal tissue is inhibited.
=== Vascular endothelium and microangiopathy === An upregulation of vascular cell adhesion molecule-1 is observed in NL tissue, indicating leukocyte aggregation and an inflammatory response. Furthermore, there is a reduced VEGF expression along with AGE-mediated cross-linking, reducing ECM fluidity. Both factors impair new vessel growth, lead to poor oxygenation, and impair tissue healing.
Sources: en.wikipedia.org
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
It acts on the growth hormone-releasing hormone receptor found on pituitary somatotroph cells. Activation of that receptor triggers growth hormone release through a cyclic AMP dependent pathway.