Abstract
Several functional proteins are identified and extracted from seaweeds. Red
seaweeds contain a higher amount of proteins compared to green and brown seaweeds.
Based on the structure, functional proteins in seaweeds can be categorized as
glycoproteins and lectins, phycobiliproteins, mycosporine-like amino acids, and
peptides and hydrolysates. Glycoproteins are oligosaccharides (glycans) bound to the
proteins with N-glycosylation or O-glycosyl linkages. Lectins are also a type of
glycoprotein with a carbohydrate-binding domain that binds to specific sugar residues.
Phycobiliproteins (PBP) are water-soluble fluorescent pigments mostly found in red
seaweeds. There are several types of phycobiliproteins, such as phycoerythrin,
phycocyanin, phycoerythrocyanins, and allophycocyanin. Mycosporine-like amino
acids (MAA) are secondary metabolites produced by marine organisms, including
seaweeds. Peptides and hydrolysates are produced by gastrointestinal digestion or
hydrolyzation processes. Several studies suggested that seaweed functional proteins
exert unique health benefits, including antioxidant, anti-obesity, antimicrobial and
antihypertensive activities. In this chapter, we will briefly describe the bioactive
properties of proteins isolated from seaweeds.