Tris
From Wikipedia, the free encyclopedia
| Tris | |
|---|---|
 |
|
| IUPAC name |
2-Amino-2-hydroxymethyl-propane-1,3-diol
|
| Other names | TRIS, Tris, Tris base, Tris buffer, TrizmaTM, Trisamine, THAM, Tromethamine, Trometamol, Tromethane |
| Identifiers | |
| CAS number | 77-86-1  |
| RTECS number | TY2900000 |
| SMILES |
C(C(CO)(CO)N)O
|
| Properties | |
| Molecular formula | C4H11NO3 |
| Molar mass | 121.14 g mol−1 |
| Appearance | White crystalline powder |
| Melting point |
>175-176°C (448-449 K) |
| Boiling point |
219°C (492 K) |
| Solubility in water | ~50 g/100 ml (25°C) in water |
| Acidity (pKa) | 8.06 |
| Hazards | |
| MSDS | External MSDS |
| R-phrases | R36, R37, R38. |
| S-phrases | S26, S36. |
| NFPA 704 |
 0
2
0
|
| Flash point | Non-flammable |
| (what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
Tris (also known as THAM) is an abbreviation of the organic compound known as tris(hydroxymethyl)aminomethane, with the formula (HOCH2)3CNH2. Tris is extensively used in biochemistry and molecular biology.[1] In biochemistry, tris is widely used as a component of buffer solutions, such as in TAE and TBE buffer, especially for solutions of nucleic acids. It is a primary amine and thus undergoes the reactions associated with typical amines, e.g. condensations with aldehydes.
Contents |
[edit] Buffering features
Tris has a pKa of 8.06, which implies that the buffer has an effective pH range between 7.0 and 9.2.
[edit] Buffer details
- The pKa declines approximately 0.03 units per degree Celsius rise in temperature.[2] [3]
- Silver-containing single-junction pH electrodes (e.g., silver chloride electrode) are incompatible with Tris (Ag-tris precipitation clogs the junction). Double-junction electrodes are resistant to this problem, and non-silver containing electrodes are immune.
- It is toxic to mammalian cells.
- A common variant of tris (aka tris base) is tris-HCl, the acid salt. When titrated to a specific pH with the corresponding counterion (OH- for tris-HCl, H+ for tris base) they are equivalent. However, the molecular weights are different and must be correctly accounted for in order to arrive at the expected buffer strength.
[edit] Buffer inhibition
- It is reported that Tris inhibits a number of enzymes [4][5], and therefore, it should be used with care when studying proteins.
[edit] Preparation
Tris is prepared in two steps from nitromethane via the intermediate (HOCH2)3CNO2 . Reduction of the latter gives tris(hydroxymethyl)aminomethane.[6]
[edit] Uses
The useful buffer range for tris (7-9) coincides with the typical physiological pH of most living organisms. This, and its low cost, make tris one of the most common buffers used in the biology/biochemistry lab.
[edit] Medical
Tris (usually known as THAM in this context) is used as alternative to sodium bicarbonate in the treatment of metabolic acidosis.[7]
[edit] See also
[edit] References
- ^ Gomori, G., Preparation of Buffers for Use in Enzyme Studies. Methods Enzymology., 1, 138-146 (1955).
- ^ El-Harakany, A.A.; Abdel Halima, F.M. and Barakat, A.O. (March 1984). "Dissociation constants and related thermodynamic quantities of the protonated acid form of tris-(hydroxymethyl)-aminomethane in mixtures of 2-methoxyethanol and water at different temperatures". J. Electroanal. Chem. 162 (1-2): 285–305. http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TGB-4K7KHSW-T-1&_cdi=5250&_user=585204&_orig=search&_coverDate=03%2F09%2F1984&_sk=998379998&view=c&wchp=dGLzVtz-zSkWb&md5=c58cb01faa3d3175e0812c84d68f04d7&ie=/sdarticle.pdf.
- ^ Vega, C.A.; Butler, R.A. et al. (October 1985). "Thermodynamics of the Dissociation of Protonated Tris(hydroxymethy1)aminomethane in 25 and 50 wt % 2-Propanol from 5 to 45 O C". J. Chem. Eng. Data 30: 376–379. http://0-pubs.acs.org.pugwash.lib.warwick.ac.uk/doi/pdf/10.1021/je00042a003?cookieSet=1.
- ^ Desmarais, WT; et al. (2002). "The 1.20 Å resolution crystal structure of the aminopeptidase from Aeromonas proteolytica complexed with Tris: A tale of buffer inhibition .". Structure 10: 1063–1072. PMID 12176384.
- ^ Ghalanbor, Z; et al. (2008). "Binding of Tris to Bacillus licheniformis alpha-amylase can affect its starch hydrolysis activity.". Protein Peptide Lett. 15: 212–214. PMID 18289113.
- ^ Sheldon B. Markofsky “Nitro Compounds, Aliphatic” Ullmann's Encyclopedia of Industrial Chemistry 2002 by Wiley-VCH, Wienheim, 2002. DOI: 10.1002/14356007.a17_401.
- ^ Kallet, RH; Jasmer RM, Luce JM et al. (April 2000). "The treatment of acidosis in acute lung injury with tris-hydroxymethyl aminomethane (THAM)". American Journal of Respiratory and Critical Care Medicine 161 (4): 1149–1153. PMID 10764304. http://ajrccm.atsjournals.org/cgi/content/full/161/4/1149.
