|
|
| Line 1: |
Line 1: |
| '''Molecular binding''' is an attractive interaction between two [[molecule]]s that results in a stable association in which the molecules are close to each other. The result of molecular binding is the formation of a '''molecular complex'''. A molecular complex in turn is a loose association involving two or more molecules. The attractive bonding between the components of a complex is normally weaker than in a [[covalent bond]].<ref name="urlIUPAC Gold Book - complex">{{cite web | url = http://goldbook.iupac.org/C01203.html | title = Definition of a molecular complex | date = 2012-08-19 | format = | work = Compendium of Chemical Terminology: Gold Book | publisher = International Union of Pure and Applied Chemistry }}</ref>
| | Hi there. Allow me begin by introducing the author, her name is Sophia. To climb is some thing I really appreciate performing. Her family life in Ohio but her husband desires them to transfer. Credit authorising is exactly where my main income comes from.<br><br>Feel free to visit my blog post :: psychic readings ([http://cspl.postech.ac.kr/zboard/Membersonly/144571 click through the up coming website page]) |
| | |
| == Types ==
| |
| | |
| Molecular binding can be classified into the following types:<ref name="pmid19053779">{{cite journal | author = Smith AJ, Zhang X, Leach AG, Houk KN | title = Beyond picomolar affinities: quantitative aspects of noncovalent and covalent binding of drugs to proteins | journal = J. Med. Chem. | volume = 52 | issue = 2 | pages = 225–33 |date=January 2009 | pmid = 19053779 | doi = 10.1021/jm800498e | url = | issn = | pmc = 2646787 }}</ref>
| |
| | |
| * [[noncovalent bonding|non-covalent]] – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
| |
| * reversible [[covalent bond|covalent]] – a chemical bond is formed, however the [[Gibbs free energy|free energy]] difference separating the noncovalently-bonded reactants from bonded product is near [[chemical equilibrium|equilibrium]] and the [[activation energy|activation barrier]] is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
| |
| * irreversible covalent – a chemical bond is formed in which the product is [[thermodynamics|thermodynamically]] much more stable than the reactants such that the reverse reaction does not take place.
| |
| | |
| == Driving force ==
| |
| | |
| In order for the complex to be stable, the [[Gibbs free energy|free energy]] of complex by definition must be lower than the solvent separated molecules. The binding may be primarily [[entropy]]-driven (release of ordered solvent molecules around the isolated molecule that results in a net increase of entropy of the system). When the solvent is water, this known as the [[hydrophobic effect]]. Alternatively the binding may be [[enthalpy]]-driven where non-covalent attractive forces such as [[electrostatic]] attraction, [[hydrogen bonding]], and [[van der Waals force|van der Waals]] / [[London dispersion force]]s are primarily responsible for the formation of a stable complex.<ref name="pmid8378312">{{cite journal | author = Miyamoto S, Kollman PA | title = What determines the strength of noncovalent association of ligands to proteins in aqueous solution? | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 90 | issue = 18 | pages = 8402–6 |date=September 1993 | pmid = 8378312 | pmc = 47364 | doi = 10.1073/pnas.90.18.8402}}</ref> Complexes that have a strong entropy contribution to formation tend to have weak enthalpy contributions. Conversely complexes that have strong enthalpy component tend to have a weak entropy component. This phenomenon is known as [[enthalpy-entropy compensation]].<ref name="pmid10508661">{{cite journal | author = Cooper A | title = Thermodynamic analysis of biomolecular interactions | journal = Curr Opin Chem Biol | volume = 3 | issue = 5 | pages = 557–63 |date=October 1999 | pmid = 10508661 | doi = 10.1016/S1367-5931(99)00008-3 }}</ref>
| |
| | |
| == Measurement ==
| |
| | |
| The [[equilibrium constant|association constant]] (K<sub>I</sub>) also known as the [[binding constant]] (K<sub>A</sub>) between the components of complex is the ratio of the concentration of the complex divided by the product of the concentrations of the isolated components at equilibrium:
| |
| | |
| :<math>A+B \rightleftharpoons AB:\log K_{I} =\log \left(\frac{[AB]}{[A][B]} \right)=pK_I </math> | |
| | |
| == Examples ==
| |
| | |
| Molecules that can participate in molecular binding include [[proteins]], [[nucleic acids]], [[carbohydrates]], [[lipids]], and small organic molecules such as [[drugs]]. Hence the types of complexes that form as a result of molecular binding include:
| |
| | |
| * protein – protein<ref name="isbn1-58829-120-0">{{cite book | author = Haian Fu | authorlink = | editor = | others = | title = Protein-protein interactions: methods and applications | edition = | language = | publisher = Humana Press | location = Totowa, NJ | year = 2004 | origyear = | pages = | quote = | isbn = 1-58829-120-0 | oclc = | doi = | url = | accessdate = }}</ref>
| |
| * protein – [[DNA]]<ref name="isbn3-540-48147-8">{{cite book | author = Harald Seitz | authorlink = | editor = | others = | title = Analytics of Protein-DNA Interactions (Advances in Biochemical Engineering / Biotechnology) | edition = | language = | publisher = Springer | location = Berlin | year = 2007 | origyear = | pages = | quote = | isbn = 3-540-48147-8 | oclc = | doi = | url = | accessdate = }}</ref>
| |
| * protein – [[hormone]]
| |
| * protein – drug<ref name="isbn3-527-30521-1">{{cite book | author = Gerd Folkers; Hans-Joachim Böhm; Gisbert Schneider; Raimund Mannhold; Hugo Kubinyi | authorlink = | editor = | others = | title = Protein-ligand interactions from molecular recognition to drug design | edition = | language = | publisher = Wiley-VCH | location = Weinheim | year = 2003 | origyear = | pages = | quote = | isbn = 3-527-30521-1 | oclc = | doi = | url = | accessdate = }}</ref>
| |
| | |
| Proteins that form stable complexes with other molecules are often referred to as [[receptor (biochemistry)|receptors]] while their binding partners are called [[ligand (biochemistry)|ligand]]s.<ref name="isbn0-471-17626-5">{{cite book | author = Klotz, Irving M. | authorlink = | editor = | others = | title = Ligand-receptor energetics: a guide for the perplexed | edition = | language = | publisher = John Wiley & Sons | location = Chichester | year = 1997 | origyear = | pages = | quote = | isbn = 0-471-17626-5 | oclc = | doi = | url = | accessdate = }}</ref>
| |
| | |
| == See also ==
| |
| * [[Receptor (biochemistry)]]
| |
| * [[Supramolecular chemistry]]
| |
| | |
| == References ==
| |
| {{Reflist}}
| |
| | |
| [[Category:Medicinal chemistry]]
| |
| [[Category:Molecular physics]]
| |
Hi there. Allow me begin by introducing the author, her name is Sophia. To climb is some thing I really appreciate performing. Her family life in Ohio but her husband desires them to transfer. Credit authorising is exactly where my main income comes from.
Feel free to visit my blog post :: psychic readings (click through the up coming website page)