Table 3.

Classification of pea protein and its molecular characteristics.

Protein	Content	Solubility	Molecular Weight	Distinct Structural Features	Reference
Globulin	65–80%	Salt solution
Legumin			320–400 kDa	Hexameric protein with six subunits. Compact Quaternary structure. Has an acidic and basic polypeptide linked by disulfide bonds	[7,78]
Vicilin			150–170 kDa	Trimeric protein. Combination of heterogenous polypeptides with no disulfide protein. Has hydrophilic surface more than legumin	[12,28]
Convicilin			180–210 kDa	It can form trimers, including N-terminal with three convicilin molecules. Contain sulfur-containing amino acid.	[60]
Albumin	10–20%	Water solution	5–80 kDa	Two major fractions: a larger albumin protein comprising two polypeptides and a minor one.	[54]
PA1	5–9%		10 kDa	Dimer	[28]
PA2	10–20%		50 kDa	Dimer	[12]
Lectins	2.5%		50 kDa	Tetramer	[16]
Lipoxygenases	<1%		n/a	n/a	[54]
Serine/trypsin protease inhibitors	<2%		10–16 kDa	Monomer	[7]
Prolamin	4–5%	Alcohol solution	n/a	Present in a small amount. Has high glutamine and proline content.	[37]
Glutelin	3–4%	Insoluble	n/a	Class of prolamin-like protein. Only soluble in dilute acid or bases. Rich in hydrophobic amino acids.	[79]