Oligomer: Difference between revisions
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m Changed "polio virus" to "polyomavirus". Poliovirus is an RNA virus which also has a VP1 capsid subunit, but the article was referencing polyomavirus, an unrelated virus to the virus that causes polio. |
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{{Short description|Molecule composed of copies of a small unit}} |
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|title =[[International Union of Pure and Applied Chemistry| IUPAC]] definition |
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[[File:15-crown-5 and monomer 3D balls.png|thumb|right|The [[15-crown-5]] [[crown ether]], a cyclic oligomer, and its monomer, [[ethylene oxide]].]] |
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|quote = '''Oligomer molecule''': A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass. |
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In [[chemistry]] and [[biochemistry]], an '''oligomer''' ({{IPAc-en|audio=En-us-Oligomer.oga|ə|ˈ|l|ɪ|g|ə|m|ər}}) is a [[molecule]] that consists of a few [[repeating unit]]s which could be derived, actually or conceptually, from smaller molecules, [[monomer|monomers]].<ref name=webster>{{cite web|title=Oligomer|url=http://www.merriam-webster.com/dictionary/oligomer|publisher=[[Merriam-Webster]]|access-date=25 October 2014}}</ref><ref name=Goldbook-Oligomer>{{GoldBookRef |title=oligomer molecule |file=O04286 }}</ref><ref name=IUPAC1966>{{cite journal|title=Glossary of basic terms in polymer science (IUPAC Recommendations 1996)|journal=[[Pure and Applied Chemistry]]|year=1996|volume=68|issue=12|pages=2287–2311|doi=10.1351/pac199668122287|last1=Jenkins|first1=A. D.|last2=Kratochvíl|first2=P.|last3=Stepto|first3=R. F. T.|last4=Suter|first4=U. W.|doi-access=free}}Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass.''</ref> The name is composed of [[Greek language|Greek]] elements ''[[wikt:oligo-|oligo-]]'', "a few" and ''[[wikt:-mer|-mer]]'', "parts". An [[adjective]] form is ''oligomeric''.<ref name=IUPAC1966/> |
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The oligomer concept is contrasted to that of a [[polymer]], which is usually understood to have a large number of units, possibly thousands or millions. However, there is no sharp distinction between these two concepts. One proposed criterion is whether the molecule's properties vary significantly with the removal of one or a few of the units.<ref name=IUPAC1966/> |
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''Note'' |
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# A molecule is regarded as having an intermediate relative molecular mass if it has properties which do vary significantly with the removal of one or a few of the units. |
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# If a part or the whole of the molecule has an intermediate relative molecular mass and essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass, it may be described as oligomeric, or by oligomer used adjectivally.<ref name="Glossary-IUPAC-1996">{{cite journal|title=Glossary of basic terms in polymer science (IUPAC Recommendations 1996)|journal=[[Pure and Applied Chemistry]]|year=1996|volume=68|issue=12|pages=2287–2311|doi=10.1351/pac199668122287|url=http://www.degruyter.com/view/j/pac.1996.68.issue-12/pac199668122287/pac199668122287.xml}}</ref> |
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An oligomer with a specific number of units is referred to by the Greek prefix denoting that number, with the ending ''-mer'': thus [[dimer (chemistry)|dimer]], [[trimer (chemistry)|trimer]], [[tetramer]], [[pentamer]], and [[hexamer]] refer to molecules with two, three, four, five, and six units, respectively. The units of an oligomer may be arranged in a linear chain (as in [[Melam (chemistry)|melam]], a dimer of [[melamine]]); a closed ring (as in [[1,3,5-trioxane]], a cyclic trimer of [[formaldehyde]]); or a more complex structure (as in [[tellurium tetrabromide]], a tetramer of {{chem2|TeBr4}} with a [[cube]]-like core). If the units are identical, one has a ''homo-oligomer''; otherwise one may use ''hetero-oligomer''. An example of a homo-oligomeric protein is [[collagen]], which is composed of three identical protein chains. |
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'''Oligomerization''': The process of converting a monomer or a mixture of monomers into an oligomer. |
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[[File:Tetrapeptide structural formulae v.1.png|thumb|right|A [[tetrapeptide]], a hetero-oligomer of the amino acids [[valine]] (green), [[glycine]] (black), [[serine]] (black), and [[alanine]] (blue). The units were joined by condensation of the [[carboxylic acid]] group –C(=O)OH of one monomer with the [[amine group]] {{chem2|H2N\s}} of the next one.]] |
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''Note'' |
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Some biologically important oligomers are macromolecules like [[protein]]s or [[nucleic acids]]; for instance, [[hemoglobin]] is a protein tetramer. An oligomer of [[amino acid]]s is called an oligopeptide or just a [[peptide]]. An [[oligosaccharide]] is an oligomer of [[monosaccharide]]s (simple sugars). An [[oligonucleotide]] is a short single-stranded fragment of [[nucleic acid]] such as [[deoxyribonucleic acid|DNA]] or [[ribonucleic acid|RNA]], or similar fragments of analogs of nucleic acids such as [[peptide nucleic acid]] or [[Morpholino]]s. |
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# An oligomerization by chain reaction carried out in the presence of a large amount of chain-transfer agent, so that the end-groups are essentially fragments of the chain-transfer agent, is termed ''telomerization''.<ref name="Glossary-IUPAC-1996" /> |
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[[File:Mpyv vp1 pentamer vp2 1sie 1cn3.png|thumb|right|A pentamer unit of the major capsid protein VP1. Each monomer is in a different color.]] |
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The units of an oligomer may be connected by [[covalent bond]]s, which may result from bond rearrangement or [[condensation reaction]]s, or by weaker forces such as [[hydrogen bond]]s. |
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The term '''multimer''' ({{IPAc-en|ˈ|m|ʌ|l|t|ᵻ|m|ər}}) is used in biochemistry for oligomers of proteins that are not covalently bound. The [[major capsid protein VP1]] that comprises the shell of [[polyomavirus|polyomaviruses]] is a self-assembling multimer of 72 pentamers held together by local electric charges. |
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| ⚫ | Many [[oil]]s are oligomeric, such as [[Liquid paraffin (medicinal)|liquid paraffin]]. [[Plasticizers]] are oligomeric [[ester]]s widely used to soften [[thermoplastics]] such as [[polyvinyl chloride|PVC]]. They may be made from monomers by linking them together, or by separation from the higher fractions of [[crude oil]]. [[Polybutene]] is an oligomeric oil used to make [[putty]]. |
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An '''oligomer''' ({{IPAc-en|audio=En-us-Oligomer.oga|ə|ˈ|l|ɪ|g|ə|m|ər}}<ref name=MerriamWebsterDef>{{cite web|title=Oligomer|url=http://www.merriam-webster.com/dictionary/oligomer|publisher=[[Merriam-Webster]]|accessdate=25 October 2014}}</ref>) (''[[wikt:oligo-|oligo-]]'', "a few" + ''[[wikt:-mer|-mer]]'', "parts") is a [[molecular complex]] of [[chemistry|chemicals]] that consists of a few [[monomer]] units, in contrast to a [[polymer]], where the number of monomers is, in principle, unlimited.<ref name="Goldbook-Oligomer">{{cite encyclopedia|encyclopedia=Compendium of Chemical Terminology (the "Gold Book")|title=Oligomer molecule|editor1-last=McNaught |editor2-first=A.D. |editor2-last=Wilkinson |edition=2|date=February 24, 2014|url=http://goldbook.iupac.org/O04286.html|ISBN=0-9678550-9-8|doi=10.1351/goldbook.O04286|accessdate=October 25, 2014|publisher=[[Blackwell Scientific]]}}</ref> [[Dimer (chemistry)|Dimers]], [[Trimer (chemistry)|trimers]], and [[tetramer]]s are, for instance, oligomers composed of two, three and four monomers, respectively. |
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'''Oligomerization''' is a chemical process that converts monomers to macromolecular complexes through a finite [[degree of polymerization]].<ref name=IUPAC1966/> [[Telomerization]] is an oligomerization carried out under conditions that result in [[chain transfer]], limiting the size of the oligomers.<ref name=Goldbook-Telomerization>{{GoldBookRef |title=telomerization |file=T06260 }}</ref><ref name=IUPAC1966 /> (This concept is not to be confused with the formation of a [[telomere]], a region of highly repetitive DNA at the end of a [[chromosome]].) |
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In [[biochemistry]], an oligomer usually refers to a macromolecular complex formed by non-covalent bonding of a few macromolecules like [[protein]]s or [[nucleic acids]]. In this sense, a homo-oligomer would be formed by few identical molecules and by contrast, a hetero-oligomer would be made of more than one, different, macromolecules. [[Collagen]] is an example of a homo-oligomeric protein that is composed of three identical protein chains. The term ''multimer'' ({{IPAc-en|ˈ|m|ʌ|l|t|ᵻ|m|ər}}) (''[[wikt:multi-|multi-]]'', "more than one" + ''[[wikt:-mer|-mer]]'', "part") is used with a meaning similar to that of ''oligomer'' in the context of proteins (although technical restrictions of word sense may exist).{{Citation needed|date=September 2015}} |
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| ⚫ | Many [[oil]]s are oligomeric, such as |
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In biochemistry, the term [[oligonucleotide]] – or, informally, "oligo" – is used for short, single-stranded nucleic acid fragments, such as [[deoxyribonucleic acid|DNA]] or [[ribonucleic acid|RNA]], or similar fragments of analogs of nucleic acids such as [[peptide nucleic acid]] or [[Morpholino]]s. Such oligos are used in [[hybridisation (molecular biology)|hybridization]] experiments (bound to glass slides or [[nylon]] membranes), as probes for [[in situ hybridization]] or in [[antisense]] experiments such as [[gene knockdown]]s.{{citation needed|date=April 2012}} It can also refer to a [[protein complex]] made of two or more [[Protein subunit|subunits]]. In this case, a complex made of several different protein subunits is called a hetero-oligomer or [[heteromer]]. When only one type of protein subunit is used in the complex, it is called a homo-oligomer or homomer. |
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'''Oligomerization''' is a chemical process that converts monomers to macromolecular complexes through a finite [[degree of polymerization]]. The actual figure for degree of polymerization is a matter of debate, often a value between 10 and 100.{{Citation needed|date=July 2010}} |
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'''[[Telomerization]]''' is the process where an oligomer forms a ''telomer'' as a result of [[chain transfer]].<ref name="Goldbook-Telomerization">{{cite encyclopedia|encyclopedia=Compendium of Chemical Terminology (the "Gold Book")|title=Telomerization|editor1-last=McNaught |editor2-first=A.D. |editor2-last=Wilkinson |edition=2|date=February 24, 2014|url=http://goldbook.iupac.org/T06260.html|ISBN=0-9678550-9-8|doi=10.1351/goldbook.T06260|accessdate=October 25, 2014|publisher=[[Blackwell Scientific]]}}</ref> A telomere is a region of highly repetitive DNA at the end of a linear chromosome. |
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==Green oil== |
==Green oil== |
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In the oil and gas industry, green oil refers to oligomers formed in all C2, C3 and C4 hydrogenation reactors of ethylene plants and other petrochemical production facilities; it is a mixture of C4 to C20 unsaturated and reactive components with about 90% aliphatic dienes and 10% of |
In the oil and gas industry, green oil refers to oligomers formed in all C2, C3, and C4 hydrogenation reactors of ethylene plants and other petrochemical production facilities; it is a mixture of C4 to C20 unsaturated and reactive components with about 90% [[aliphatic]] [[diene|dienes]] and 10% of [[alkanes]] plus [[alkenes]].<ref>{{cite web|url=http://www.pall.com/main/fuels-and-chemicals/green-oil-contaminant-separation-37657.page|title=Chemicals & Polymers|website=www.pall.com}}</ref> Different heterogeneous and homogeneous catalysts are operative in producing green oils via the oligomerization of alkenes.<ref>{{cite journal|last1=Ghashghaee|first1=Mohammad|title=Heterogeneous catalysts for gas-phase conversion of ethylene to higher olefins|journal=Rev. Chem. Eng.|volume=34|issue=5|pages=595–655|doi=10.1515/revce-2017-0003|url=https://www.degruyter.com/view/j/revce.ahead-of-print/revce-2017-0003/revce-2017-0003.xml|year=2018|s2cid=103664623 }}</ref> |
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==See also== |
==See also== |
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* [[Merosity|Oligomery (botany)]] |
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* [[Protein oligomer]] |
* [[Protein oligomer]] |
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==References== |
==References== |
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{{Reflist}} |
{{Reflist}} |
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==External links== |
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*{{Commonscatinline}} |
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[[Category:Polymer chemistry]] |
[[Category:Polymer chemistry]] |
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Latest revision as of 17:57, 27 June 2024
In chemistry and biochemistry, an oligomer (/əˈlɪɡəmər/ ) is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.[1][2][3] The name is composed of Greek elements oligo-, "a few" and -mer, "parts". An adjective form is oligomeric.[3]
The oligomer concept is contrasted to that of a polymer, which is usually understood to have a large number of units, possibly thousands or millions. However, there is no sharp distinction between these two concepts. One proposed criterion is whether the molecule's properties vary significantly with the removal of one or a few of the units.[3]
An oligomer with a specific number of units is referred to by the Greek prefix denoting that number, with the ending -mer: thus dimer, trimer, tetramer, pentamer, and hexamer refer to molecules with two, three, four, five, and six units, respectively. The units of an oligomer may be arranged in a linear chain (as in melam, a dimer of melamine); a closed ring (as in 1,3,5-trioxane, a cyclic trimer of formaldehyde); or a more complex structure (as in tellurium tetrabromide, a tetramer of TeBr4 with a cube-like core). If the units are identical, one has a homo-oligomer; otherwise one may use hetero-oligomer. An example of a homo-oligomeric protein is collagen, which is composed of three identical protein chains.
Some biologically important oligomers are macromolecules like proteins or nucleic acids; for instance, hemoglobin is a protein tetramer. An oligomer of amino acids is called an oligopeptide or just a peptide. An oligosaccharide is an oligomer of monosaccharides (simple sugars). An oligonucleotide is a short single-stranded fragment of nucleic acid such as DNA or RNA, or similar fragments of analogs of nucleic acids such as peptide nucleic acid or Morpholinos.
The units of an oligomer may be connected by covalent bonds, which may result from bond rearrangement or condensation reactions, or by weaker forces such as hydrogen bonds. The term multimer (/ˈmʌltɪmər/) is used in biochemistry for oligomers of proteins that are not covalently bound. The major capsid protein VP1 that comprises the shell of polyomaviruses is a self-assembling multimer of 72 pentamers held together by local electric charges.
Many oils are oligomeric, such as liquid paraffin. Plasticizers are oligomeric esters widely used to soften thermoplastics such as PVC. They may be made from monomers by linking them together, or by separation from the higher fractions of crude oil. Polybutene is an oligomeric oil used to make putty.
Oligomerization is a chemical process that converts monomers to macromolecular complexes through a finite degree of polymerization.[3] Telomerization is an oligomerization carried out under conditions that result in chain transfer, limiting the size of the oligomers.[4][3] (This concept is not to be confused with the formation of a telomere, a region of highly repetitive DNA at the end of a chromosome.)
Green oil
[edit]In the oil and gas industry, green oil refers to oligomers formed in all C2, C3, and C4 hydrogenation reactors of ethylene plants and other petrochemical production facilities; it is a mixture of C4 to C20 unsaturated and reactive components with about 90% aliphatic dienes and 10% of alkanes plus alkenes.[5] Different heterogeneous and homogeneous catalysts are operative in producing green oils via the oligomerization of alkenes.[6]
See also
[edit]References
[edit]- ^ "Oligomer". Merriam-Webster. Retrieved 25 October 2014.
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "oligomer molecule". doi:10.1351/goldbook.O04286
- ^ a b c d e Jenkins, A. D.; Kratochvíl, P.; Stepto, R. F. T.; Suter, U. W. (1996). "Glossary of basic terms in polymer science (IUPAC Recommendations 1996)". Pure and Applied Chemistry. 68 (12): 2287–2311. doi:10.1351/pac199668122287.Quote: Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass.
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "telomerization". doi:10.1351/goldbook.T06260
- ^ "Chemicals & Polymers". www.pall.com.
- ^ Ghashghaee, Mohammad (2018). "Heterogeneous catalysts for gas-phase conversion of ethylene to higher olefins". Rev. Chem. Eng. 34 (5): 595–655. doi:10.1515/revce-2017-0003. S2CID 103664623.
External links
[edit]Media related to Oligomers at Wikimedia Commons
