Bovine serum albumin
| albumin | |
|---|---|
 |
|
| Identifiers | |
| Organism | |
| Symbol | ALB |
| Entrez | 280717 |
| RefSeq (mRNA) | NM_180992 |
| RefSeq (Prot) | NP_851335 |
| UniProt | P02769 |
| Other data | |
| Chromosome | 6: 91.54 - 91.57 Mb |
Bovine serum albumin (also known as BSA or "Fraction V") is a serum albumin protein derived from cows. It is often used as a protein concentration standard.
The nickname "Fraction V" refers to albumin being the fifth fraction of the original Edwin Cohn purification methodology that made use of differential solubility characteristics of plasma proteins. By manipulating solvent concentrations, pH, salt levels, and temperature, Cohn was able to pull out successive "fractions" of blood plasma. The process was first commercialized with human albumin for medical use and later adopted for production of BSA.
Contents |
[edit] Properties
The full-length BSA precursor protein is 607 amino acids in length. An N-terminal 18-residue signal peptide is cut off from the precursor protein upon secretion, hence the initial protein product contains 589 amino acid residues. An additional 4 amino acids is cleaved to yield the mature BSA protein that contains 585 amino acids.
| Peptide | Position | Length | MW Da |
|---|---|---|---|
| Full length precursor | 1 – 607 | 607 | 69,324 |
| Signal peptide | 1 – 18 | 18 | 2,107 |
| Propeptide | 19 – 22 | 4 | 478 |
| Mature protein | 25 – 607 | 583 | 66,463 |
Physical properties of BSA:
- Number of amino acid residues: 585
- Molecular weight: 66,463 Da (= 66.5 kDa)
- isoelectric point in water at 25 °C: 4.7
- Extinction coefficient of 43,824 M−1cm−1 at 279 nm[1]
- Dimensions: 140 X 40 X 40 Å3 (prolate ellipsoid where a = b < c)[2]
[edit] Applications
BSA has numerous biochemical applications including ELISAs (Enzyme-Linked Immunosorbent Assay), immunoblots, and immunohistochemistry. It is also used as a nutrient in cell and microbial culture.[citation needed] In restriction digests, BSA is used to stabilize some enzymes during digestion of DNA and to prevent adhesion of the enzyme to reaction tubes, pipet tips, and other vessels.[3] This protein does not affect other enzymes that do not need it for stabilization. BSA is also commonly used to determine the quantity of other proteins, by comparing an unknown quantity of protein to known amounts of BSA (see Bradford protein assay). BSA is used because of its stability, its lack of effect in many biochemical reactions, and its low cost, since large quantities of it can be readily purified from bovine blood, a byproduct of the cattle industry.
[edit] See also
[edit] References
- ^ Peters T (1975). Putman FW. ed. The Plasma Proteins. Academic Press. pp. 133–181.
- ^ Wright AK, Thompson MR (February 1975). "Hydrodynamic structure of bovine serum albumin determined by transient electric birefringence". Biophys. J. 15 (2 Pt 1): 137–41. doi:10.1016/S0006-3495(75)85797-3. PMC 1334600. PMID 1167468. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1334600.
- ^ "BSA FAQ". Invitrogen. http://www.neb.com/nebecomm/products/faqproductB9001.asp#572. Retrieved 19 January 2012.
[edit] Further reading
- Wise SA, Watters RL (2010-06-30). "Bovine Serum Albumin (7 % Solution)" (pdf). Certificate of Analysis. United States National Institute of Standards & Technology. https://www-s.nist.gov/srmors/certificates/927d.pdf?CFID=11628267&CFTOKEN=f682f88a759516bc-B4D66BFA-E23D-27B4-7C85AA1E5BC84277&jsessionid=b430384deb613141a202. Retrieved 2011-12-22.
- Hirayama K, Akashi S, Furuya M, Fukuhara K (December 1990). "Rapid confirmation and revision of the primary structure of bovine serum albumin by ESIMS and Frit-FAB LC/MS". Biochem. Biophys. Res. Commun. 173 (2): 639–46. doi:10.1016/S0006-291X(05)80083-X. PMID 2260975.
- Zhang M, Desai T, Ferrari M (May 1998). "Proteins and cells on PEG immobilized silicon surfaces". Biomaterials 19 (10): 953–60. doi:10.1016/S0142-9612(98)00026-X. PMID 9690837. http://physio.ucsf.edu/desai/papers/1998/Proteins%20and%20cells%20on%20PEG%20immobilized%20silicon%20surfaces..pdf.
