WordNet

a substance that exerts some force or effect
a businessman who buys or sells for another in exchange for a commission (同)factor, broker
any agent or representative of a federal agency or bureau (同)federal agent
a representative who acts on behalf of other persons or organizations
an active and efficient cause; capable of producing a certain effect; "their research uncovered new disease agents"
how long something has existed; "it was replaced because of its age"
a time of life (usually defined in years) at which some particular qualification or power arises; "she was now of school age"; "tall for his eld" (同)eld
begin to seem older; get older; "The death of his wife caused him to age fast"
make older; "The death of his child aged him tremendously"

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『代理人』;周旋人 / 働き(作用)を起こすもの;作用物,薬剤 / (政府機関,特にFBI,CIAなどの)部員,機関員
〈U〉(一般に)『年齢』,寿命;〈C〉(個々の)『年齢』,年 / 〈U〉成年(おとなとしての資格・権利を得る年齢;通例18または21歳) / 〈U〉『老齢』;《集合的に》老人たち / 〈U〉(人生の)『一時期』;〈C〉世代(generation) / 〈U〉〈C〉《しばしばA-》(歴史上の)『時代』 / 〈C〉《話》長い間 / 年をとる,ふける;〈物が〉古くなる / 〈年〉'を'とらせる;〈物〉'を'古びさせる

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/01/10 08:42:57」(JST)

wiki en

A chaotropic agent is a substance which disrupts the structure of, and denatures, macromolecules such as proteins and nucleic acids (e.g. DNA and RNA). Chaotropic solutes increase the entropy of the system by interfering with intramolecular interactions mediated by non-covalent forces such as hydrogen bonds, van der Waals forces, and hydrophobic effects. Macromolecular structure and function is dependent on the net effect of these forces (see protein folding), therefore it follows that an increase in chaotropic solutes in a biological system will denature macromolecules, reduce enzymatic activity and induce stress on a cell (i.e., a cell will have to synthesize stress protectants). Tertiary protein folding is dependent on hydrophobic forces from amino acids throughout the sequence of the protein. Chaotropic solutes decrease the net hydrophobic effect of hydrophobic regions because of a disordering of water molecules adjacent to the protein. This solubilises the hydrophobic region in the solution, thereby denaturing the protein. This is also directly applicable to the hydrophobic region in lipid bilayers; if a critical concentration of a chaotropic solute is reached (in the hydrophobic region of the bilayer) then membrane integrity will be compromised, and the cell will lyse.^[1]

Chaotropic salts that dissociate in solution exert chaotropic effects via different mechanisms. Whereas chaotropic compounds such as ethanol interfere with non-covalent intramolecular forces as outlined above, salts can have chaotropic properties by shielding charges and preventing the stabilization of salt bridges. Hydrogen bonding is stronger in non-polar media, so salts, which increase the chemical polarity of the solvent, can also destabilize hydrogen bonding. Mechanistically this is because there are insufficient water molecules to effectively solvate the ions. This can result in ion-dipole interactions between the salts and hydrogen bonding species which are more favorable than normal hydrogen bonds.^[2]

Chaotropic agents include:

Butanol
Ethanol
Guanidinium chloride
Lithium perchlorate
Lithium acetate
Magnesium chloride
Phenol
Propanol
Sodium dodecyl sulfate
Thiourea
Urea

References

^ Bhaganna, P; Volkers RJM, Bell ANW, Kluge K, Timson DJ, McGrath JW, Ruijssenaars HJ, Hallsworth JE (2010). "Hydrophobic substances induce water stress in microbial cells". Microbial Biotechnology 3 (6): 701–716. doi:10.1111/j.1751-7915.2010.00203.x.
^ Collins, KD (1997). "Charge density-dependent strength of hydration and biological structures.". Biophys. J. 72: 65–76.

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English Journal

A functional dual-coated (FDC) microtiter plate method to replace the botulinum toxin LD(50) test.

Liu YY, Rigsby P, Sesardic D, Marks JD, Jones RG.SourceDivision of Bacteriology, National Institute for Biological Standards and Control, Health Protection Agency, South Mimms, Hertfordshire EN6 3QG, UK.
Analytical biochemistry.Anal Biochem.2012 Jun 1;425(1):28-35. Epub 2012 Mar 6.
Conventional capture ("Sandwich") ELISAs equally detect denatured inactive and native active botulinum type A toxin. Light chain endoprotease activity assays also fail to distinguish between various inactive molecules including partially denatured and fragmented material still retaining this proteas
PMID 22406430

Recovery of active anti TNF-α ScFv through matrix-assisted refolding of bacterial inclusion bodies using CIM monolithic support.

Sushma K, Bilgimol CJ, Vijayalakshmi MA, Satheeshkumar PK.SourceCentre for Bioseparation Technology, VIT University, Vellore 632014, Tamil Nadu, India.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.J Chromatogr B Analyt Technol Biomed Life Sci.2012 Apr 1;891-892:90-3. Epub 2012 Feb 16.
Anti TNF-α molecules are important as therapeutic agents for many of the autoimmune diseases in chronic stage. Here we report the expression and purification of a recombinant single chain variable fragment (ScFv) specific to TNF-α from inclusion bodies. In contrast to the conventional on column re
PMID 22386363

Japanese Journal

Solubilization and Refolding of Bacterial Inclusion Body Proteins

Singh Surinder Mohan,Panda Amulya Kumar
Journal of bioscience and bioengineering 99(4), 303-310, 2005-04-25
… It is assumed that restoration of this native-like secondary structure using mild solubilization conditions will help in improved recovery of bioactive protein in comparison to solubilization using a high concentration of chaotropic agent. …
NAID 110002695665