Inchemistry,adisulfide(ordisulphideinBritish English) is a compound containing aR−S−S−R′functional groupor theS2−
2anion.The linkage is also called anSS-bondor sometimes adisulfide bridgeand usually derived from twothiolgroups.
Ininorganic chemistry,the anion appears in a few rare minerals, but the functional group has tremendous importance inbiochemistry.Disulfide bridges formed between thiol groups in twocysteineresidues are an important component of the tertiary and quaternary structure ofproteins.
Compounds of the formR−S−S−Hare usually calledpersulfidesinstead.
Organic disulfides
editStructure
editDisulfides have a C-S-S-Cdihedral angleapproaching 90°. The S-S bond length is 2.03 Å indiphenyl disulfide,[1]similar to that in elemental sulfur.
Two kinds of disulfides are recognized, symmetric and unsymmetric. Symmetrical disulfides are compounds of the formulaRSSR.Most disulfides encountered in organo sulfur chemistry are symmetrical disulfides.Unsymmetrical disulfides(also calledheterodisulfidesormixed disulfides) are compounds of the formulaRSSR'.Unsymmetrical disulfide are less common in organic chemistry, but many disulfides in nature are unsymmetrical. Illustrative of a symmetric disulfide iscystine.
Properties
editThe disulfide bonds are strong, with a typicalbond dissociation energyof 60 kcal/mol (251 kJ mol−1). However, being about 40% weaker thanC−CandC−Hbonds, the disulfide bond is often the "weak link" in many molecules. Furthermore, reflecting thepolarizabilityof divalent sulfur, theS−Sbond is susceptible to scission by polar reagents, bothelectrophilesand especiallynucleophiles(Nu):[2]
The disulfide bond is about 2.05Åin length, about 0.5 Å longer than aC−Cbond. Rotation about theS−Saxis is subject to a low barrier. Disulfides show a distinct preference fordihedral anglesapproaching 90°. When the angle approaches 0° or 180°, then the disulfide is a significantly better oxidant.
Disulfides where the two R groups are the same are called symmetric, examples beingdiphenyl disulfideanddimethyl disulfide.When the two R groups are not identical, the compound is said to be an asymmetric or mixed disulfide.[3]
Although thehydrogenationof disulfides is usually not practical, the equilibrium constant for the reaction provides a measure of the standard redox potential for disulfides:
This value is about −250 mV versus thestandard hydrogen electrode(pH = 7). By comparison, the standard reduction potential forferrodoxinsis about −430 mV.
Synthesis
editDisulfide bonds are usually formed from theoxidationofsulfhydryl(−SH) groups, especially in biological contexts.[4]The transformation is depicted as follows:
A variety of oxidants participate in this reaction including oxygen andhydrogen peroxide.Such reactions are thought to proceed viasulfenic acidintermediates. In the laboratory,iodinein the presence of base is commonly employed to oxidize thiols to disulfides. Several metals, such as copper(II) and iron(III)complexesaffect this reaction.[5]Alternatively, disulfide bonds in proteins often formed bythiol-disulfide exchange:
Such reactions are mediated by enzymes in some cases and in other cases are under equilibrium control, especially in the presence of a catalytic amount of base.
Thealkylationof alkali metal di- andpolysulfidesgives disulfides. "Thiokol" polymers arise whensodium polysulfideis treated with an alkyl dihalide. In the converse reaction, carbanionic reagents react with elemental sulfur to afford mixtures of the thioether, disulfide, and higher polysulfides. These reactions are often unselective but can be optimized for specific applications.
Synthesis of unsymmetrical disulfides (heterodisulfides)
editMany specialized methods have been developed for forming unsymmetrical disulfides. Reagents that deliver the equivalent of "RS+"react with thiols to give asymmetrical disulfides:[4]
whereR″2Nis thephthalimidogroup. Bunte salts,derivatives of the typeRSSO−3Na+are also used to generate unsymmetrical disulfides:[6]
Reactions
editThe most important aspect of disulfide bonds is their scission, as theS−Sbond is usually the weakest bond in a molecule. Many specializedorganic reactionshave been developed to cleave the bond.
A variety of reductants reduce disulfides tothiols.Hydride agents are typical reagents, and a common laboratory demonstration "uncooks" eggs withsodium borohydride.[7]Alkali metals effect the same reaction more aggressively:followed by protonation of the resulting metal thiolate:
In biochemistry labwork, thiols such as β-mercaptoethanol(β-ME) ordithiothreitol(DTT) serve as reductants throughthiol-disulfide exchange.The thiol reagents are used in excess to drive the equilibrium to the right: The reductanttris(2-carboxyethyl)phosphine(TCEP) is useful, beside being odorless compared to β-ME and DTT, because it is selective, working at both alkaline and acidic conditions (unlike DTT), is more hydrophilic and more resistant to oxidation in air. Furthermore, it is often not needed to remove TCEP before modification of protein thiols.[8]
In Zincke cleavage, halogens oxidize disulfides to asulfenyl halide:[9]
More unusually, oxidation of disulfides gives firstthiosulfinatesand thenthiosulfonates:[10]
- RSSR + [O] → RS(=O)SR
- RS(=O)SR + [O] → RS(=O)2SR
Thiol-disulfide exchange
editIn thiol–disulfide exchange, athiolategroup−S−displaces onesulfuratomin a disulfide bond−S−S−.The original disulfide bond is broken, and its other sulfur atom is released as a new thiolate, carrying away the negative charge. Meanwhile, a new disulfide bond forms between the attacking thiolate and the original sulfur atom.[11][12]
Thiolates, not thiols, attack disulfide bonds. Hence, thiol–disulfide exchange is inhibited at lowpH(typically, below 8) where the protonated thiol form is favored relative to the deprotonated thiolate form. (ThepKaof a typical thiol group is roughly 8.3, but can vary due to its environment.)
Thiol–disulfide exchange is the principal reaction by which disulfide bonds are formed and rearranged in aprotein.The rearrangement of disulfide bonds within a protein generally occurs via intra-protein thiol–disulfide exchange reactions; a thiolate group of acysteineresidue attacks one of the protein's own disulfide bonds. This process of disulfide rearrangement (known asdisulfide shuffling) does not change the number of disulfide bonds within a protein, merely their location (i.e., which cysteines are bonded). Disulfide reshuffling is generally much faster than oxidation/reduction reactions, which change the number of disulfide bonds within a protein. The oxidation and reduction of protein disulfide bondsin vitroalso generally occurs via thiol–disulfide exchange reactions. Typically, the thiolate of a redox reagent such asglutathione,dithiothreitolattacks the disulfide bond on a protein forming amixed disulfide bondbetween the protein and the reagent. This mixed disulfide bond when attacked by another thiolate from the reagent, leaves the cysteine oxidized. In effect, the disulfide bond is transferred from the protein to the reagent in two steps, both thiol–disulfide exchange reactions.
Thein vivooxidation and reduction of protein disulfide bonds by thiol–disulfide exchange is facilitated by a protein calledthioredoxin.This small protein, essential in all known organisms, contains two cysteine amino acid residues in avicinalarrangement (i.e., next to each other), which allows it to form an internal disulfide bond, or disulfide bonds with other proteins. As such, it can be used as a repository of reduced or oxidized disulfide bond moieties.
Occurrence in biology
editOccurrence in proteins
editDisulfide bonds can be formed underoxidising conditionsand play an important role in the folding and stability of some proteins, usually proteins secreted to the extracellular medium.[3]Since most cellular compartments arereducing environments,in general, disulfide bonds are unstable in thecytosol,with some exceptions as noted below, unless asulfhydryl oxidaseis present.[13]
Disulfide bonds in proteins are formed between thethiolgroups ofcysteineresidues by the process ofoxidative folding.The other sulfur-containing amino acid,methionine,cannot form disulfide bonds. A disulfide bond is typically denoted by hyphenating the abbreviations for cysteine, e.g., when referring toribonuclease Athe "Cys26–Cys84 disulfide bond", or the "26–84 disulfide bond", or most simply as "C26–C84"[14]where the disulfide bond is understood and does not need to be mentioned. The prototype of a protein disulfide bond is the two-amino-acid peptidecystine,which is composed of twocysteineamino acids joined by a disulfide bond. The structure of a disulfide bond can be described by itsχssdihedral anglebetween the Cβ−Sγ−Sγ−Cβatoms, which is usually close to ±90°.
The disulfide bond stabilizes the folded form of a protein in several ways:
- It holds two portions of the protein together, biasing the protein towards the folded topology. That is, the disulfide bonddestabilizes the unfolded formof the protein by lowering itsentropy.
- The disulfide bond may form the nucleus of ahydrophobic coreof the folded protein, i.e., local hydrophobic residues may condense around the disulfide bond and onto each other throughhydrophobic interactions.
- Related to 1 and 2, the disulfide bondlinkstwo segments of the protein chain,increasesthe effective local concentration of protein residues, andlowersthe effective local concentration of water molecules. Since water molecules attack amide-amidehydrogen bondsand break upsecondary structure,a disulfide bond stabilizes secondary structure in its vicinity. For example, researchers have identified several pairs of peptides that are unstructured in isolation, but adopt stable secondary and tertiary structure upon formation of a disulfide bond between them.
Adisulfide speciesis a particular pairing of cysteines in a disulfide-bonded protein and is usually depicted by listing the disulfide bonds in parentheses, e.g., the "(26–84, 58–110) disulfide species". Adisulfide ensembleis a grouping of all disulfide species with the same number of disulfide bonds, and is usually denoted as the 1S ensemble, the 2S ensemble, etc. for disulfide species having one, two, etc. disulfide bonds. Thus, the (26–84) disulfide species belongs to the 1S ensemble, whereas the (26–84, 58–110) species belongs to the 2S ensemble. The single species with no disulfide bonds is usually denoted as R for "fully reduced". Under typical conditions,disulfide reshufflingis much faster than the formation of new disulfide bonds or their reduction; hence, the disulfide species within an ensemble equilibrate more quickly than between ensembles.
The native form of a protein is usually a single disulfide species, although some proteins may cycle between a few disulfide states as part of their function, e.g.,thioredoxin.In proteins with more than two cysteines, non-native disulfide species may be formed, which are almost always misfolded. As the number of cysteines increases, the number of nonnative species increases factorially.
This sectionis missing informationabout intermolecular disulfide bonds of the protein-protein and protein-thiol varieties.(November 2023) |
In bacteria and archaea
editDisulfide bonds play an important protective role forbacteriaas a reversible switch that turns a protein on or off when bacterial cells are exposed tooxidationreactions.Hydrogen peroxide(H2O2) in particular could severely damageDNAand kill thebacteriumat low concentrations if not for the protective action of the SS-bond.Archaeatypically have fewer disulfides than higher organisms.[15]
In eukaryotes
editIneukaryoticcells, in general, stable disulfide bonds are formed in the lumen of theRER(rough endoplasmic reticulum) and themitochondrial intermembrane spacebut not in thecytosol.This is due to the more oxidizing environment of the aforementioned compartments and more reducing environment of the cytosol (seeglutathione). Thus disulfide bonds are mostly found in secretory proteins, lysosomal proteins, and the exoplasmic domains of membrane proteins.
There are notable exceptions to this rule. For example, many nuclear and cytosolic proteins can become disulfide-crosslinked during necrotic cell death.[16]Similarly, a number of cytosolic proteins which have cysteine residues in proximity to each other that function as oxidation sensors orredoxcatalysts; when the reductive potential of the cell fails, they oxidize and trigger cellular response mechanisms. The virusVacciniaalso produces cytosolic proteins and peptides that have many disulfide bonds; although the reason for this is unknown presumably they have protective effects against intracellular proteolysis machinery.
Disulfide bonds are also formed within and betweenprotaminesin thespermchromatinof manymammalianspecies.
Disulfides in regulatory proteins
editAs disulfide bonds can be reversibly reduced and re-oxidized, the redox state of these bonds has evolved into a signaling element. Inchloroplasts,for example, the enzymatic reduction of disulfide bonds has been linked to the control of numerous metabolic pathways as well as gene expression. The reductive signaling activity has been shown, thus far, to be carried by theferredoxin-thioredoxin system,channeling electrons from the light reactions ofphotosystem Ito catalytically reduce disulfides in regulated proteins in a light dependent manner. In this way chloroplasts adjust the activity of key processes such as theCalvin–Benson cycle,starchdegradation,ATPproduction and gene expression according to light intensity. Additionally, It has been reported that disulfides plays a significant role on redox state regulation of Two-component systems (TCSs), which could be found in certain bacteria including photogenic strain. A unique intramolecular cysteine disulfide bonds in the ATP-binding domain of SrrAB TCs found inStaphylococcus aureusis a good example of disulfides in regulatory proteins, which the redox state of SrrB molecule is controlled by cysteine disulfide bonds, leading to the modification of SrrA activity including gene regulation.[17]
In hair and feathers
editOver 90% of the dry weight ofhaircomprises proteins calledkeratins,which have a high disulfide content, from the amino acid cysteine. The robustness conferred in part by disulfide linkages is illustrated by the recovery of virtually intact hair from ancient Egyptian tombs.Feathershave similar keratins and are extremely resistant to protein digestive enzymes. The stiffness of hair and feather is determined by the disulfide content. Manipulating disulfide bonds in hair is the basis for thepermanent wavein hairstyling. Reagents that affect the making and breaking of S−S bonds are key, e.g.,ammonium thioglycolate.The high disulfide content of feathers dictates the high sulfur content of bird eggs. The high sulfur content of hair and feathers contributes to the disagreeable odor that results when they are burned.
In disease
editCystinosisis a condition where cystine precipitates as a solid in various organs. This accumulation interferes with bodily function and can be fatal. This disorder can be resolved by treatment withcysteamine.[18]Cysteamine acts to solubilize the cystine by (1) forming the mixed disulfide cysteine-cysteamine, which is more soluble and exportable, and (2) reducing cystine to cysteine.
Inorganic disulfides
editThe disulfideanionisS2−
2,or−S−S−.In disulfide, sulfur exists in the reduced state with oxidation number −1. Its electron configuration then resembles that of achlorineatom. It thus tends to form a covalent bond with another S−center to formS2−
2group, similar to elemental chlorine existing as the diatomic Cl2.Oxygenmay also behave similarly, e.g. inperoxidessuch as H2O2.Examples:
- Hydrogen disulfide(S2H2), the simplest inorganic disulfide
- Disulfur dichloride(S2Cl2), a distillable liquid.
- Irondisulfide (FeS2), orpyrite.
Related compounds
editThiosulfoxidesare orthogonally isomeric with disulfides, having the second sulfur branching from the first and not partaking in a continuous chain, i.e. >S=S rather than −S−S−.
Disulfide bonds are analogous but more common than relatedperoxide,thioselenide,anddiselenidebonds. Intermediate compounds of these also exist, for example thioperoxides (also known as oxasulfides) such ashydrogen thioperoxide,have the formula R1OSR2(equivalently R2SOR1). These are isomeric tosulfoxidesin a similar manner to the above; i.e. >S=O rather than −S−O−.
Thiuram disulfides,with the formula (R2NCSS)2,are disulfides but they behave distinctly because of thethiocarbonylgroup.
Compounds with three sulfur atoms, such as CH3S−S−SCH3,are called trisulfides, or trisulfide bonds.
Misnomers
editDisulfide is also used to refer to compounds that contain two sulfide (S2−) centers. The compoundcarbon disulfide,CS2is described with the structural formula i.e. S=C=S. This molecule is not a disulfide in the sense that it lacks a S-S bond. Similarly,molybdenum disulfide,MoS2,is not a disulfide in the sense again that its sulfur atoms are not linked.
Applications
editRubber manufacturing
editThevulcanizationofrubberresults in crosslinking groups which consist of disulfide (and polysulfide) bonds; in analogy to the role of disulfides in proteins, the S−S linkages in rubber strongly affect the stability andrheologyof the material.[19]Although the exact mechanism underlying the vulcanization process is not entirely understood (as multiple reaction pathways are present but the predominant one is unknown), it has been extensively shown that the extent to which the process is allowed to proceed determines the physical properties of the resulting rubber- namely, a greater degree of crosslinking corresponds to a stronger and more rigid material.[19][20]The current conventional methods of rubber manufacturing are typically irreversible, as the unregulated reaction mechanisms can result in complex networks of sulfide linkages; as such, rubber is considered to be athermosetmaterial.[19][21]
Covalent adaptable networks
editDue to their relatively weakbond dissociation energy(in comparison to C−C bonds and the like), disulfides have been employed incovalent adaptable network(CAN) systems in order to allow for dynamic breakage and reformation of crosslinks.[22]By incorporating disulfide functional groups as crosslinks between polymer chains, materials can be produced which are stable at room temperature while also allowing for reversible crosslink dissociation upon application of elevated temperature.[20]The mechanism behind this reaction can be attributed to the cleavage of disulfide linkages (RS−SR) intothiyl radicals(2 RS•) which can subsequently reassociate into new bonds, resulting in reprocessability andself-healingcharacteristics for the bulk material.[22]However, since the bond dissociation energy of the disulfide bond is still fairly high, it is typically necessary to augment the bond with adjacent chemistry that can stabilize the unpaired electron of the intermediate state.[21][22]As such, studies usually employaromaticdisulfides or disulfidediamine (RNS−SNR) functional groups to encourage the dynamic dissociation of the S−S bond; these chemistries can result in the bond dissociation energy being reduced to half (or even less) of its prior magnitude.[20][21][22]
In practical terms, disulfide-containing CANs can be used to impartrecyclabilityto polymeric materials while still exhibiting physical properties similar to that of thermosets.[21][22]Typically, recyclability is restricted tothermoplasticmaterials, as said materials consist of polymer chains which are not bonded to each other at the molecular level; as a result, they can be melted down and reformed (as the addition of thermal energy allows the chains to untangle, move past each other, and adopt new configurations), but this comes at the expense of their physical robustness.[22]Meanwhile, conventional thermosets contain permanent crosslinks which bolster theirstrength,toughness,creepresistance, and the like (as the bonding between chains provides resistance to deformation at the macroscopic level), but due to the permanence of said crosslinks, these materials cannot be reprocessed akin to thermoplastics.[21][22]However, due to the dynamic nature of the crosslinks in disulfide CANs, they can be designed to exhibit the best attributes of both of the aforementioned material types. Studies have shown that disulfide CANs can be reprocessed multiple times with negligible degradation in performance while also exhibiting creep resistance,glass transition,anddynamic modulusvalues comparable to those observed in similar conventional thermoset systems.[20][21]
See also
edit- Thiosulfinate– Functional group
- Diselenides inorganoselenium chemistry
References
edit- ^Lee, J. D.; Bryant, M. W. R. (1969). "The Crystal Structure of Diphenyl Disulphide".Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry.25(10): 2094–2101.Bibcode:1969AcCrB..25.2094L.doi:10.1107/S0567740869005188.
- ^Cremlyn, R. J. (1996).An Introduction to Organosulfur Chemistry.Chichester: John Wiley and Sons.ISBN0-471-95512-4.
- ^abSevier, C. S.; Kaiser, C. A. (2002)."Formation and transfer of disulphide bonds in living cells".Nature Reviews Molecular Cell Biology.3(11): 836–847.doi:10.1038/nrm954.PMID12415301.S2CID2885059.
- ^abWitt, D. (2008). "Recent developments in disulfide bond formation".Synthesis.2008(16): 2491–2509.doi:10.1055/s-2008-1067188.
- ^Kreitman, Gal Y. (March 5, 2017)."Copper(II)-Mediated Hydrogen Sulfide and Thiol Oxidation to Disulfides and Organic Polysulfanes and Their Reductive Cleavage in Wine: Mechanistic Elucidation and Potential Applications".Journal of Agricultural and Food Chemistry.65(12): 2564–2571.doi:10.1021/acs.jafc.6b05418.PMID28260381.Retrieved31 May2021.
- ^M. E. Alonso; H. Aragona (1978). "Sulfide Synthesis in Preparation of Unsymmetrical Dialkyl Disulfides: Sec-butyl Isopropyl Disulfide".Org. Synth.58:147.doi:10.15227/orgsyn.058.0147.
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- Hubacher, Max H. (1935). "o-Nitrophenylsulfur Chloride ".Organic Syntheses.15:45.doi:10.15227/orgsyn.015.00452.
- Douglass, Irwin B.; Norton, Richard V. (1960). "Methanesulfinyl Chloride".Organic Syntheses.40:62.doi:10.15227/orgsyn.040.0062.
- ^Nikolai S. Zefirov, Nikolai V. Zyk, Elena K. Beloglazkina, Andrei G. Kutateladze (1993). "Thiosulfonates: Synthesis, Reactions and Practical Applications".Sulfur Reports.14:223–240.doi:10.1080/01961779308055018.
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:CS1 maint: multiple names: authors list (link) - ^Gilbert, H. F. (1990). "Molecular and Cellular Aspects of Thiol–Disulfide Exchange".Advances in Enzymology and Related Areas of Molecular Biology.Advances in Enzymology and Related Areas of Molecular Biology. Vol. 63. pp. 69–172.doi:10.1002/9780470123096.ch2.ISBN9780470123096.PMID2407068.
- ^Gilbert, H. F. (1995). "Thiol/disulfide exchange equilibria and disulfide bond stability".Biothiols, Part A: Monothiols and Dithiols, Protein Thiols, and Thiyl Radicals.Methods in Enzymology.Vol. 251. pp. 8–28.doi:10.1016/0076-6879(95)51107-5.ISBN9780121821524.PMID7651233.
- ^Hatahet, F.; Nguyen, V. D.; Salo, K. E.; Ruddock, L. W. (2010)."Disruption of reducing pathways is not essential for efficient disulfide bond formation in the cytoplasm ofE. coli".Microbial Cell Factories.9(67): 67.doi:10.1186/1475-2859-9-67.PMC2946281.PMID20836848.
- ^Ruoppolo, M.; Vinci, F.; Klink, T. A.; Raines, R. T.; Marino, G. (2000). "Contribution of individual disulfide bonds to the oxidative folding of ribonuclease A".Biochemistry.39(39): 12033–12042.doi:10.1021/bi001044n.PMID11009618.
- ^Ladenstein, R.; Ren, B. (2008). "Reconsideration of an early dogma, saying" there is no evidence for disulfide bonds in proteins from archaea "".Extremophiles.12(1): 29–38.doi:10.1007/s00792-007-0076-z.PMID17508126.S2CID11491989.
- ^Samson, Andre L.; Knaupp, Anja S.; Sashindranath, Maithili; Borg, Rachael J.; Au, Amanda E.-L.; Cops, Elisa J.; Saunders, Helen M.; Cody, Stephen H.; McLean, Catriona A. (2012-10-25)."Nucleocytoplasmic coagulation: an injury-induced aggregation event that disulfide crosslinks proteins and facilitates their removal by plasmin".Cell Reports.2(4): 889–901.doi:10.1016/j.celrep.2012.08.026.ISSN2211-1247.PMID23041318.
- ^Tiwari, Nitija; López-Redondo, Marisa; Miguel-Romero, Laura; Kulhankova, Katarina; Cahill, Michael P.; Tran, Phuong M.; Kinney, Kyle J.; Kilgore, Samuel H.; Al-Tameemi, Hassan; Herfst, Christine A.; Tuffs, Stephen W.; Kirby, John R.; Boyd, Jeffery M.; McCormick, John K.; Salgado-Pabón, Wilmara; Marina, Alberto; Schlievert, Patrick M.; Fuentes, Ernesto J. (19 May 2020)."The SrrAB two-component system regulates Staphylococcus aureus pathogenicity through redox sensitive cysteines".Proceedings of the National Academy of Sciences.117(20): 10989–10999.Bibcode:2020PNAS..11710989T.doi:10.1073/pnas.1921307117.PMC7245129.PMID32354997.
- ^Besouw, Martine; Masereeuw, Rosalinde; Van Den Heuvel, Lambert; Levtchenko, Elena (2013). "Cysteamine: An Old Drug with new Potential".Drug Discovery Today.18(15–16): 785–792.doi:10.1016/j.drudis.2013.02.003.PMID23416144.
- ^abcAkiba, M.; Hashim, A.S. (1997)."Vulcanization and crosslinking in elastomers".Progress in Polymer Science.22(3): 475–521.doi:10.1016/S0079-6700(96)00015-9– viaElsevier Science Direct.
- ^abcdMutlu, Hatice; Theato, Patrick (2020)."Making the Best of Polymers with Sulfur–Nitrogen Bonds: From Sources to Innovative Materials".Macromolecular Rapid Communications.41(13): 2000181.doi:10.1002/marc.202000181.PMID32462759.S2CID218975603.
- ^abcdefBin Rusayyis, Mohammed; Torkelson, John (2021)."Reprocessable covalent adaptable networks with excellent elevated-temperature creep resistance: facilitation by dynamic, dissociative bis(hindered amino) disulfide bonds".Polymer Chemistry.12(18): 2760–2771.doi:10.1039/D1PY00187F.S2CID234925061.
- ^abcdefgZheng, Jie; Png, Zhuang Mao; Ng, Shi Hoe; Tham, Guo Xiong; Ye, Enyi; Goh, Shermin S.; Loh, Xian Jun; Li, Zibiao (2021)."Vitrimers: Current research trends and their emerging applications".Materials Today.51:586–625.doi:10.1016/j.mattod.2021.07.003.S2CID237649642.
Further reading
edit- Sela, M.; Lifson, S. (1959). "The reformation of disulfide bridges in proteins".Biochimica et Biophysica Acta.36(2): 471–478.doi:10.1016/0006-3002(59)90188-X.PMID14444674.
- Stark, G. R.; Stern, K.; Atala, A.; Yoo, J. (1977).Cleavage at cysteine after cyanylation.Methods in Enzymology. Vol. 47. pp. 129–132.doi:10.1016/j.ymeth.2008.09.005.PMID927170.
- Thornton, J. M. (1981). "Disulphide bridges in globular proteins".Journal of Molecular Biology.151(2): 261–287.doi:10.1016/0022-2836(81)90515-5.PMID7338898.
- Thannhauser, T. W.; Konishi, Y.; Scheraga, H. A. (1984). "Sensitive quantitative analysis of disulfide bonds in polypeptides and proteins".Analytical Biochemistry.138(1): 181–188.doi:10.1016/0003-2697(84)90786-3.PMID6547275.
- Wu, J.; Watson, J. T. (1998). "Optimization of the cleavage reaction for cyanylated cysteinyl proteins for efficient and simplified mass mapping".Analytical Biochemistry.258(2): 268–276.doi:10.1006/abio.1998.2596.PMID9570840.
- Futami, J.; Tada, H.; Seno, M.; Ishikami, S.; Yamada, H. (2000). "Stabilization of human RNAse 1 by introduction of a disulfide bond between residues 4 and 118".Journal of Biochemistry.128(2): 245–250.doi:10.1093/oxfordjournals.jbchem.a022747.PMID10920260.
- Wittenberg, G.; Danon, A. (2008). "Disulfide bond formation in chloroplasts: Formation of disulfide bonds in signaling chloroplast proteins".Plant Science.175(4): 459–466.doi:10.1016/j.plantsci.2008.05.011.
- Kadokura, Hiroshi; Katzen, Federico; Beckwith, Jon (2003). "Protein Disulfide Bond Formation in Prokaryotes".Annual Review of Biochemistry.72(1): 111–135.doi:10.1146/annurev.biochem.72.121801.161459.PMID12524212.
- Tu, B. P.; Weissman, J. S. (2004)."Oxidative protein folding in eukaryotes: mechanisms and consequences".The Journal of Cell Biology.164(3): 341–346.doi:10.1083/jcb.200311055.PMC2172237.PMID14757749.
- Ellgaard, Lars; Ruddock, Lloyd W. (2005)."The human protein disulphide isomerase family: substrate interactions and functional properties".EMBO Reports.6(1): 28–32.doi:10.1038/sj.embor.7400311.PMC1299221.PMID15643448.
External links
edit- Media related toDisulfidesat Wikimedia Commons