Recognition roles of the carbohydrate glycotopes of human and bovine lactoferrins in lectin-N-glycan interactions.
BACKGROUND
Lactoferrin is an iron-binding protein belonging to the transferrin family. In addition to iron homeostasis, lactoferrin is also thought to have anti-microbial, anti-inflammatory, and anticancer activities. Previous studies showed that all lactoferrins are glycosylated in the human body, but the recognition roles of their carbohydrate glycotopes have not been well addressed.


METHODS
The roles of human and bovine lactoferrins involved in lectin-N-glycan recognition processes were analyzed by enzyme-linked lectinosorbent assay with a panel of applied and microbial lectins.


CONCLUSIONS
Both native and asialo human/bovine lactoferrins reacted strongly with four Man-specific lectins - Concanavalia ensiformis agglutinin, Morniga M, Pisum sativum agglutinin, and Lens culinaris lectin. They also reacted well with PA-IIL, a LFuc>Man-specific lectin isolated from Pseudomonas aeruginosa. Both human and bovine lactoferrins also recognized a sialic acid specific lectin-Sambucus nigra agglutinin, but not their asialo products. Both native and asialo bovine lactoferrins, but not the human ones, exhibited strong binding with a GalNAc>Gal-specific lectin-Wisteria floribunda agglutinin. Human native lactoferrins and its asialo products bound well with four Gal>GalNAc-specific type-2 ribosome inactivating protein family lectins-ricin, abrin-a, Ricinus communis agglutinin 1, and Abrus precatorius agglutinin (APA), while the bovine ones reacted only with APA.


CONCLUSIONS
This study provides essential knowledge regarding the different roles of bioactive sites of lactoferrins in lectin-N-glycan recognition processes.
Glyco-Immunochemistry Research Labortory, Institute of Molecular and Cellular Biology, College of Medicine, Chang Gung University, Tao-yuan, Taiwan.
Meng-Hsiu
MH
Yen
Albert M
AM
Wu
Zhangung
Z
Yang
Yu-Ping
YP
Gong
En-Tzu
ET
Chang
D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D002417:Cattle; D002686:Chitin / Q000737:chemistry / Q000378:metabolism; D000939:Epitopes / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007781:Lactoferrin / Q000737:chemistry / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D037121:Plant Lectins / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011550:Pseudomonas aeruginosa / Q000378:metabolism
D018829:Adhesins, Bacterial; D002241:Carbohydrates; D000939:Epitopes; D037102:Lectins; D037121:Plant Lectins; D011134:Polysaccharides; C038692:adhesin, Pseudomonas; D002686:Chitin; D007781:Lactoferrin; D019158:N-Acetylneuraminic Acid