lyophilized powder raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-26 and is reviewed periodically as new material appears.
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.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
| Property | Value | Notes |
|---|---|---|
| Duration with linker | Several days | Reported in early human work |
| Duration without linker | Tens of minutes | Short plasma residence |
| Albumin attachment site | Cysteine-34 | Covalent maleimide reaction |
| Primary receptor | Pituitary GHRH receptor | Stimulates growth hormone release |
| Downstream marker | Insulin-like growth factor 1 | Indirect measure of activity |
=== Filming === Every exterior (outdoor) scene was filmed in Zimbabwe, as were roughly 70% of interior shots. The remaining interior shots were all filmed in England. Principal filming took place primarily in Harare in Zimbabwe because of the tense political situation in South Africa at the time of shooting. The film includes a dramatised depiction of the Soweto uprising and massacre, which occurred on 16 June 1976. Indiscriminate firing by police killed and injured hundreds of black South African schoolchildren during a mostly peaceful protest march.
Firearms is a first-person shooter mod for Half-Life which originated from a Quake modification. Initially developed in 1998, Firearms was created as a quasi-realistic team-based FPS. The mod's main feature is the large amount of usable weapons in the game.
Blood smear to evaluate cell morphology Iron panel to evaluate for concurrent iron deficiency JAK2 mutation testing Serum erythropoeitin (EPO) levels Oxygen saturation (usually via pulse oximetry or blood gas tests) or oxygen dissociation tests
Sources: en.wikipedia.org
== Biogenesis == The attachment of the heme group is physically separated from the protein biosynthesis. Proteins are synthesized within the cytoplasm and endoplasmic reticulum, while the maturation of cytochromes c occurs in the periplasm of prokaryotes, the intermembrane space of mitochondria or the stroma of chloroplasts. Several biochemical pathways have been discovered that differ depending on organism.
Different cecropins act on different types of human cancer cells and show activity at concentrations that are not harmful to normal cells. For example, a recent study of Cecropins A and B demonstrated strongly cytotoxic activity against four bladder cancer cell lines, while benign murine and human fibroblasts were not susceptible to Cecropin A or B. Cecropins from many insect species have been shown to be active against a diverse range of human cancer cell lines. For example, Mdcec, a cecropin originating from the common housefly, has been shown to have an antiproliferative effect on human hepatocellular carcinoma cell line BEL-7402 without affecting normal liver cells. Flow cytometry and RT-PCR experiments revealed that treatment with Mdcec increased expression of pro-apoptotic genes such as caspase-3, leading to cancer cell death. These same genes did not show significant expression changes in healthy cells upon treatment with Mdcec. This suggests a degree of specificity which has promise for development of novel cancer therapies. Further supporting therapeutic efficacy, a study of cecropin A affirmed that cecropin A selectively lyses leukemia cells while exerting little effect on normal lymphocytes. In the same study, chemotherapy drugs cytarabine and 5-fluorouracil synergize with cecropin A in vitro to enhance cytotoxic effects on leukemia cells. This indicates potential for therapeutic application of antimicrobial peptides in cancer, where treatment with cecropins could lower the required dosage of chemotherapy drugs, reducing undesirable side effects.
The district's borders, which correspond to the former city's borders, are: Victoria Park Avenue (facing the rest of Toronto) to the west, the Rouge River, the Little Rouge Creek and the Scarborough-Pickering Townline (facing Pickering) to the east, Steeles Avenue (facing Markham) to the north, and Lake Ontario to the south. Topographically, the district is dominated by two watersheds, Highland Creek and the Rouge River. Highland Creek lies almost entirely within Scarborough and occupies approximately 70% of its total area. It occupies the western half of Scarborough, while the Rouge River flows through the eastern portion. Both of these rivers flow into Lake Ontario. Due to the location of the Lakeshore CN railway right-of-way, both river deltas are constricted to narrow channels where they flow into the lake. Highland Creek is the most urbanized watershed in Toronto with about 85% of its land use devoted to urban uses. Some sections of the river run through parks and remain in a fairly natural state, while other parts run through industrial or residential districts where the flow is often diverted or channelled. Sections of the creek are marked by deep ravines and valleys, which contain little or no urban development. The deep valley the creek cuts in its bottom sections remains primarily parkland, with little or no development taking place within the valley. Conversely, the Rouge River valley has parts which are still in a natural, wooded state.
Sources: en.wikipedia.org
[NH4][CH3CO2] → CH3C(O)NH2 + H2O Alternatively acetamide can be obtained in excellent yield via ammonolysis of acetylacetone under conditions commonly used in reductive amination. It can also be made from anhydrous acetic acid, acetonitrile and very well dried hydrogen chloride gas, using an ice bath, alongside more valuable reagent acetyl chloride. Yield is typically low (up to 35%), and the acetamide made this way is generated as a salt with HCl.
== Localization of pyruvate decarboxylation == In eukaryotic cells the pyruvate decarboxylation occurs inside the mitochondrial matrix, after transport of the substrate, pyruvate, from the cytosol. The transport of pyruvate into the mitochondria is via the transport protein pyruvate translocase. Pyruvate translocase transports pyruvate in a symport fashion with a proton (across the inner mitochondrial membrane), which may be considered to be a form of secondary active transport, but further confirmation/support may be needed for the usage of "secondary active transport" descriptor here (Note: the pyruvate transportation method via the pyruvate translocase appears to be coupled to a proton gradient according to S. Papa et al., 1971, seemingly matching secondary active transport in definition). Alternative sources say "transport of pyruvate across the outer mitochondrial membrane appears to be easily accomplished via large non-selective channels such as voltage-dependent anion channels, which enable passive diffusion" and transport across inner mitochondrial membrane is mediated by mitochondrial pyruvate carrier 1 (MPC1) and mitochondrial pyruvate carrier 2 (MPC2). Upon entry into the mitochondrial matrix, the pyruvate is decarboxylated, producing acetyl-CoA (and carbon dioxide and NADH). This irreversible reaction traps the acetyl-CoA within the mitochondria (the acetyl-CoA can only be transported out of the mitochondrial matrix under conditions of high oxaloacetate via the citrate shuttle, a TCA intermediate that is normally sparse).
== History == Protein C's anticoagulant role in the human body was first noted by Seegers et al. in 1960, who gave protein C its original name, autoprothrombin II-a. Protein C was first isolated by Johan Stenflo from bovine plasma in 1976, and Stenflo determined it to be a vitamin K-dependent protein. He named it protein C because it was the third protein ("peak C") that eluted from a DEAE-Sepharose ion-exchange chromotograph. Seegers was, at the time, searching for vitamin K-dependent coagulation factors undetected by clotting assays, which measure global clotting function. Soon after this, Seegers recognised Stenflo's discovery was identical with his own. Activated protein C was discovered later that year, and in 1977 it was first recognised that APC inactivates Factor Va. In 1980, Vehar and Davie discovered that APC also inactivates Factor VIIIa, and soon after, Protein S was recognised as a cofactor by Walker. In 1982, a family study by Griffin et al. first associated protein C deficiency with symptoms of venous thrombosis. Homozygous protein C deficiency and the consequent serious health effects were described in 1984 by several scientists. cDNA cloning of protein C was first performed in 1984 by Beckmann et al. which produced a map of the gene responsible for producing protein C in the liver. In 1987 a seminal experiment was performed (Taylor et al.) whereby it was demonstrated that activated protein C prevented coagulopathy and death in baboons infused with lethal concentrations of E. coli. In 1993, a heritable resistance to APC was detected by Dahlbäck et al.
=== Fragment-based === The most common of these uses a group contribution method and is termed cLogP. It has been shown that the log P of a compound can be determined by the sum of its non-overlapping molecular fragments (defined as one or more atoms covalently bound to each other within the molecule). Fragmentary log P values have been determined in a statistical method analogous to the atomic methods (least-squares fitting to a training set). In addition, Hammett-type corrections are included to account of electronic and steric effects. This method in general gives better results than atomic-based methods, but cannot be used to predict partition coefficients for molecules containing unusual functional groups for which the method has not yet been parameterized (most likely because of the lack of experimental data for molecules containing such functional groups).
Sources: en.wikipedia.org
A maleimide moiety reacts with the thiol of cysteine-34, forming a covalent bond. The reaction occurs in circulation without enzymatic catalysis.
The group is intended to alter distribution and persistence, not receptor engagement. The peptide portion still binds the pituitary receptor, so the primary difference is duration rather than potency.
Not firmly. Early reports describe several days for the extended form, but independent confirmations are sparse, and values vary with assay method and study design.
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.