The isoelectric point (pI) of albumin is 4.7.
The isoelectric point (pI) is the pH at which a molecule carries no net electrical charge. In the case of albumin, a major protein found in blood plasma, this occurs at a pH of 4.7. This means that at this pH, the number of positive and negative charges on the albumin molecule are equal, resulting in a neutral net charge.
Understanding the pI of albumin is important for various biochemical techniques, such as:
- Isoelectric focusing: A technique used to separate proteins based on their isoelectric points.
- Protein purification: The pI can be used to determine conditions for precipitating or selectively binding albumin to a matrix.
Albumin's pI being slightly acidic (4.7) is due to the relative abundance of acidic amino acid residues (like aspartic acid and glutamic acid) compared to basic amino acid residues (like lysine and arginine) in its structure.
