Tris
| Tris |
|
2-Amino-2-hydroxymethyl-propane-1,3-diol
|
Other names
TRIS, Tris, Tris base, Tris buffer,
TrizmaTM, Trisamine, THAM,
Tromethamine, Trometamol, Tromethane
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| Identifiers |
| CAS number |
77-86-1 Y |
| PubChem |
6503 |
| ChemSpider |
6257 Y |
| UNII |
023C2WHX2V Y |
| KEGG |
D00396 Y |
| ChEBI |
CHEBI:9754 N |
| ChEMBL |
CHEMBL1200391 N |
| RTECS number |
TY2900000 |
| Jmol-3D images |
Image 1 |
|
|
-
InChI=1S/C4H11NO3/c5-4(1-6,2-7)3-8/h6-8H,1-3,5H2 Y
Key: LENZDBCJOHFCAS-UHFFFAOYSA-N Y
InChI=1/C4H11NO3/c5-4(1-6,2-7)3-8/h6-8H,1-3,5H2
Key: LENZDBCJOHFCAS-UHFFFAOYAN
|
| 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) |
8.30 |
| Hazards |
| MSDS |
External MSDS |
| R-phrases |
R36, R37, R38. |
| S-phrases |
S26, S36. |
| Main hazards |
Irritant |
| NFPA 704 |
|
| Flash point |
Non-flammable |
N (verify) (what is: Y/N?)
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.
Buffering features
Tris has a pKa of 8.06 at 25°C , which implies that the buffer has an effective pH range between 7.1 and 9.0.
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.
- A common form of tris is tris-HCl, which is the acid salt. When titrated to when pH = pKa with the corresponding counterion (OH- for tris-HCl, H+ for tris base) they have equivalent concentrations. However, the molecular weights are different and must be correctly accounted for in order to arrive at the expected buffer strength.
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.
Preparation
Tris is prepared in two steps from nitromethane via the intermediate (HOCH2)3CNO2. Reduction of the latter gives tris(hydroxymethyl)aminomethane.[6]
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. Tris is also used as a primary standard to standardize acid solutions for chemical analysis.
Medical
Tris (usually known as THAM in this context) is used as alternative to sodium bicarbonate in the treatment of metabolic acidosis.[7]
See also
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. (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. doi:10.1016/S0022-0728(84)80171-0.
- ^ Vega, C.A.; Butler, R.A. et al. (1985). "Thermodynamics of the Dissociation of Protonated Tris(hydroxymethy1)aminomethane in 25 and 50 wt % 2-Propanol from 5 to 45 °C". J. Chem. Eng. Data 30 (4): 376–379. doi:10.1021/je00042a003.
- ^ 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 (8): 1063–1072. doi:10.1016/S0969-2126(02)00810-9. 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 (2): 212–214. doi:10.2174/092986608783489616. PMID 18289113.
- ^ Markofsky, Sheldon B. (2000). Nitro Compounds, Aliphatic. doi:10.1002/14356007.a17_401.
- ^ Kallet, RH; Jasmer RM, Luce JM et al. (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.