myofibril
Definition
Target type: cellularcomponent
The contractile element of skeletal and cardiac muscle; a long, highly organized bundle of actin, myosin, and other proteins that contracts by a sliding filament mechanism. [ISBN:0815316194]
The myofibril is the basic contractile unit of muscle fibers. It is composed of repeating sarcomeres, which are the functional units of muscle contraction. The sarcomere is bounded by Z-lines, which are protein structures that anchor the thin filaments (actin) and provide a framework for the myofibril. The thick filaments (myosin) are located in the center of the sarcomere, and they overlap with the thin filaments. The myosin filaments have globular heads that bind to the actin filaments, and these interactions are responsible for muscle contraction. In addition to the actin and myosin filaments, the sarcomere also contains other proteins, such as tropomyosin and troponin, which regulate muscle contraction. The myofibril is surrounded by a network of sarcoplasmic reticulum, which is a specialized endoplasmic reticulum that stores and releases calcium ions. Calcium ions are essential for muscle contraction, and they are released from the sarcoplasmic reticulum in response to a nerve impulse. The myofibril is also surrounded by a plasma membrane called the sarcolemma, which is responsible for transmitting the nerve impulse to the sarcoplasmic reticulum. The myofibril is a complex and highly organized structure that is responsible for muscle contraction. The arrangement of the actin and myosin filaments, the presence of other proteins, and the surrounding sarcoplasmic reticulum and sarcolemma all contribute to the myofibril's ability to contract and generate force.'
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Proteins (3)
| Protein | Definition | Taxonomy |
|---|---|---|
| Myosin-2 | [no definition available] | Bos taurus (cattle) |
| ATP-sensitive inward rectifier potassium channel 8 | An ATP-sensitive inward rectifier potassium channel 8 that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q15842] | Homo sapiens (human) |
| Proteasome subunit alpha type-6 | A proteasome subunit alpha type-6 that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
Compounds (25)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| chlorpromazine | chlorpromazine : A substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropanamine moiety. Chlorpromazine: The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup. | organochlorine compound; phenothiazines; tertiary amine | anticoronaviral agent; antiemetic; dopaminergic antagonist; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; phenothiazine antipsychotic drug |
| clomipramine | clomipramine : A dibenzoazepine that is 10,11-dihydro-5H-dibenzo[b,f]azepine which is substituted by chlorine at position 3 and in which the hydrogen attached to the nitrogen is replaced by a 3-(dimethylamino)propyl group. One of the more sedating tricyclic antidepressants, it is used as the hydrochloride salt for the treatment of depression as well as obsessive-compulsive disorder and phobias. Clomipramine: A tricyclic antidepressant similar to IMIPRAMINE that selectively inhibits the uptake of serotonin in the brain. It is readily absorbed from the gastrointestinal tract and demethylated in the liver to form its primary active metabolite, desmethylclomipramine. | dibenzoazepine | anticoronaviral agent; antidepressant; EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor; serotonergic antagonist; serotonergic drug; serotonin uptake inhibitor |
| methixene | methixene: RN given refers to parent cpd; structure | piperidines; thioxanthenes | antiparkinson drug; histamine antagonist; muscarinic antagonist |
| thioridazine | thioridazine : A phenothiazine derivative having a methylsulfanyl subsitituent at the 2-position and a (1-methylpiperidin-2-yl)ethyl] group at the N-10 position. Thioridazine: A phenothiazine antipsychotic used in the management of PHYCOSES, including SCHIZOPHRENIA. | phenothiazines; piperidines | alpha-adrenergic antagonist; dopaminergic antagonist; EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; first generation antipsychotic; H1-receptor antagonist; serotonergic antagonist |
| triflupromazine | triflupromazine : A member of the class of phenothiazines that is 10H-phenothiazine having a trifluoromethyl subsitituent at the 2-position and a 3-(dimethylamino)propyl group at the N-10 position. Triflupromazine: A phenothiazine used as an antipsychotic agent and as an antiemetic. | organofluorine compound; phenothiazines; tertiary amine | anticoronaviral agent; antiemetic; dopaminergic antagonist; first generation antipsychotic |
| n-cyano-n'-(1,1-dimethylpropyl)-n''-(3-pyridinyl)guanidine | N-cyano-N'-(1,1-dimethylpropyl)-N''-(3-pyridinyl)guanidine: potassium channel opener | pyridines | |
| cromakalim | Cromakalim: A potassium-channel opening vasodilator that has been investigated in the management of hypertension. It has also been tried in patients with asthma. (Martindale, The Extra Pharmacopoeia, 30th ed, p352) | ||
| zeneca zd 6169 | Zeneca ZD 6169: an ATP-sensitive potassium channel opener; structure given in first source | ||
| bortezomib | amino acid amide; L-phenylalanine derivative; pyrazines | antineoplastic agent; antiprotozoal drug; protease inhibitor; proteasome inhibitor | |
| cromakalim | 1-benzopyran | ||
| sdz 283-910 | SDZ 283-910: structure in first source | ||
| benzyloxycarbonylleucyl-leucyl-leucine aldehyde | benzyloxycarbonylleucyl-leucyl-leucine aldehyde: proteasome inhibitor N-benzyloxycarbonyl-L-leucyl-L-leucyl-L-leucinal : A tripeptide that is L-leucyl-L-leucyl-L-leucine in which the C-terminal carboxy group has been reduced to the corresponding aldehyde and the N-terminal amino group is protected as its benzyloxycarbonyl derivative. | amino aldehyde; carbamate ester; tripeptide | proteasome inhibitor |
| zm226600 | ZM226600: an ATP-sensitive potassium channel opener; structure in first source | anilide | |
| blebbistatin | (S)-blebbistatin : The (S)-enantiomer of blebbistatin. | blebbistatin; tertiary alpha-hydroxy ketone | |
| benzyloxycarbonyl-phe-ala-fluormethylketone | cathepsin B inhibitor : A cysteine protease inhibitor which inhibits cathepsin B (EC 3.4.22.1). | ||
| am 404 | anilide | ||
| lactacystin | lactam; S-substituted L-cysteine | ||
| clasto-lactacystin beta-lactone | clasto-lactacystin beta-lactone: active metabolite of lactacystin; inhibits 20 S proteasome; structure in first source | ||
| way 133537 | |||
| marizomib | marizomib: a proteasome inhibitor from a marine bacterium Salinospora; structure in first source | beta-lactone; gamma-lactam; organic heterobicyclic compound; organochlorine compound; salinosporamide | antineoplastic agent; proteasome inhibitor |
| carfilzomib | epoxide; morpholines; tetrapeptide | antineoplastic agent; proteasome inhibitor | |
| tyropeptin a | tyropeptin A: proteasome inhibitors produced by Kitasatospora sp. MK993-dF2; structure in first source | dipeptide | |
| belactosin a | belactosin A: isolated from Streptomyces; structure in first source | ||
| oprozomib | ONX 0912: antineoplastic; an orally active proteasome inhibitor; structure in first source | ||
| ixazomib | ixazomib : A glycine derivative that is the amide obtained by formal condensation of the carboxy group of N-(2,5-dichlorobenzoyl)glycine with the amino group of [(1R)-1-amino-3-methylbutyl]boronic acid. The active metabolite of ixazomib citrate, it is used in combination therapy for treatment of multiple myeloma. ixazomib: a proteasome inhibitor with antineoplastic activity; MLN2238 is the biologically active form of MLN9708; structure in first source | benzamides; boronic acids; dichlorobenzene; glycine derivative | antineoplastic agent; apoptosis inducer; drug metabolite; orphan drug; proteasome inhibitor |