Search results
Results from the WOW.Com Content Network
The isoelectric point (pI, pH(I), IEP), is the pH at which a molecule carries no net electrical charge or is electrically neutral in the statistical mean. The standard nomenclature to represent the isoelectric point is pH(I). [1] However, pI is also used. [2] For brevity, this article uses pI.
For this reason isoelectric point precipitation is most often used to precipitate contaminant proteins, rather than the target protein. The precipitation of casein during cheesemaking, or during production of sodium caseinate, is an isoelectric precipitation.
It is a byproduct of the manufacturing of cheese or casein and has several commercial uses. Sweet whey is a byproduct resulting from the manufacture of rennet types of hard cheese, like cheddar or Swiss cheese. Acid whey (also known as sour whey) is a byproduct brought out during the making of acid types of dairy products, such as strained yogurt.
The isoelectric point of casein is 4.6. Since milk's pH is 6.6, casein has a negative charge in milk. The purified protein is water-insoluble. While it is also insoluble in neutral salt solutions, it is readily dispersible in dilute alkalis and in salt solutions such as aqueous sodium oxalate and sodium acetate.
The isoelectric point is the pH at which a compound - in this case a protein - has no net charge. A protein's isoelectric point or PI can be determined using the pKa of the side chains, if the amino (positive chain) is able to cancel out the carboxyl (negative) chain, the protein would be at its PI.
The major protein in whey is β-lactoglobulin, followed by α-lactalbumin (β-lactoglobulin ≈ 65%, α-lactalbumin ≈ 25%, serum albumin ≈ 8%, other ≈ 2%). β-lactoglobulin is a lipocalin protein, and can bind many hydrophobic molecules, suggesting a role in their transport. β-lactoglobulin has also been shown to be able to bind iron via siderophores [7 ...
Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin and immunoglobulins. [1] Glycomacropeptide also makes up the third largest component but is not a protein.
The LRRN3 protein is 708 amino acids in length. The molecular weight of this protein is 79,424 daltons, with an isoelectric point of 8.02. [9] It is known to be a single-pass type I membrane protein because it spans the membrane once, with its N-terminus on the extracellular side of the membrane, and its signal sequence is removed.