Anti-nutritional characteristics and mechanism of soybean agglutinin LI PAN 1 ;JIAWEI LIU 1 ;MOHAMMED HAMDY FAROUK 2, *;GUIXIN QIN 1, *;NAN BAO 1 ;YUAN ZHAO 1 ;HUI SUN 1 1 Key Laboratory of Animal Production, Product Quality and Security, Ministry of Education, Key Laboratory of Animal Nutrition and Feed Science, College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China 2 Animal Production Department, Faculty of Agriculture, Al-Azhar University, Cairo, 11884, Egypt Key words: Soybean agglutinin, Autophagy, Cell apoptosis, Anti-nutritional functions, Cell signaling Abstract: Soybean agglutinin (SBA) is an important anti-nutritional factor in soybean. SBA can induce animal growth inhibition, cause pathological changes of intestinal tissue, and decrease in the immune system functioning. Recently, a great deal of research has been done on the effects of SBA on cell morphology, division, apoptosis, autophagy, as well as the correlated signal transduction pathway. This review mainly covers the chemical and biological characteristics of SBA, describes the multifaceted aspects of SBA anti-nutritional functions, and highlights the possible cellular and molecular mechanism of anti-nutritional effects of SBA. This review has important implications for the prevention and treatment of SBA-induced diseases, drug development, processing techniques of plant products, prevention of food- borne toxins, as well as human and animal health protection. Introduction Soybean agglutinin (SBA), also known as lectin, is a major anti-nutritional factor (ANF) in soybean seeds and products. Such substance represents about 10% of the total protein in mature soybean seeds. SBA can resist the enzymatic digestion and keep its biological activity throughout the entire intestinal tract due to its stability of the structure (Carbanaro et al., 1997; Draaijer et al., 1989). SBA can interact with the mucosal cells of the digestive tract, and finally leading to a series of anti-nutritional effects on animals. At present, a large number of studies have been carried out to describe the chemical and biological characteristics of SBA and the anti-nutritional mechanisms of SBA. Therefore, the herein review aims to describe the main chemical and biological functions of SBA, describes the multifaceted aspects of SBA anti-nutritional functions, and highlights the anti-nutritional mechanisms of SBA. This review provides some help for the systematic understanding of the related progress of SBA. The main chemical and biological characteristics of SBA The chemical characteristics of SBA SBA has a typical four-stage structure of legume agglutinin with a molecular weight of 120 kDa, an isoelectric point of 5.81, a sedimentation coefficient of 6.05, and sedimentation with 7S protein in ultracentrifugation. SBA is composed of four subunits, each of which has a molecular weight of about 30 kDa. Each subunit has a covalently linked oligosaccharide chain containing 9 mannose and 2 N-phthaloyl-glucosamine (Man 9 GlcNAc 2 ). The sugar chain of each subunit in SBA is covalently linked with the amino-N of the 75th aspartame residue of the peptide chain (Asn-75) in the form of an N-glp- glucosamine bond. The sugar chain is located at the atypical interface of the subunit and interacts with the amino acid residue of the adjacent subunit. Each subunit of SBA also contains a closely bound Ca 2+ and Mn 2+ (De Boeck et al., 1984). Additionally, there have a lot of hydrogen bonds and hydrophobic forces between the two monomers in the SBA molecule. Therefore, SBA is more stable than other legume family lectins. Based on the structure characteristic of SBA, it can form specific binding with N-acetyl-D-galactosamine or galactose (Vojdani et al., 2020). Such specific-binding of SBA to the sugar is not targeted at the sugar molecules in plant cells but on the surface of microorganisms or animal cells. This specific binding of SBA is also the prerequisite and *Address correspondence to: Mohammed Hamdy Farouk, mhfarouk@jlau.edu.cn; Guixin Qin, qgx@jlau.edu.cn Received: 15 September 2020; Accepted: 21 December 2020 BIOCELL ech T Press Science 2021 45(3): 451-459 Doi: 10.32604/biocell.2021.014289 www.techscience.com/journal/biocell This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.