The name "biglycan" was proposed in an article by Fisher, Termine and Young in an article in the Journal of Biological Chemistry in 1989 because the proteoglycan contained two GAG chains; formerly it was known as proteoglycan-I (PG-I).
Biglycan consists of a protein core containing leucine-rich repeat regions and two glycosaminoglycan (GAG) chains consisting of either chondroitin sulfate (CS) or dermatan sulfate (DS), with DS being more abundant in most connective tissues. The CS/DS chains are attached at amino acids 5 and 10 in human biglycan. The composition of the GAG chains has been reported as varying according to tissue of origin. Non-glycanated forms of biglycan (no GAG chains) increase with age in human articular cartilage.
The composition of GAG chains of biglycan and decorin originating from the same tissue has been reported to be similar.
The structure of biglycan core protein is highly conserved across species; over 90% homology has been reported for rat, mouse, bovine and human biglycan core proteins.
Biglycan is believed to play a role in the mineralization of bone. Knock-out mice that have had the gene for biglycan suppressed (Bgn -/-) have an osteoporosis-like phenotype with reduced growth rate and lower bone mass than mice that can express biglycan.
Biglycan core protein binds to the growth factorsBMP-4 and influences its bioactivity. It has also been reported that the presence of biglycan is necessary for BMP-4 to exert its effects on osteoblasts. There is also evidence that biglycan binds to TGF-beta 1.
^Traupe H, van den Ouweland AM, van Oost BA, Vogel W, Vetter U, Warren ST, Rocchi M, Darlison MG, Ropers HH (June 1992). "Fine mapping of the human biglycan (BGN) gene within the Xq28 region employing a hybrid cell panel". Genomics. 13 (2): 481–3. doi:10.1016/0888-7543(92)90279-2. PMID1612609.
^Cheng F, Heinegård D, Malmström A, Schmidtchen A, Yoshida K, Fransson LA (October 1994). "Patterns of uronosyl epimerization and 4-/6-O-sulphation in chondroitin/dermatan sulphate from decorin and biglycan of various bovine tissues". Glycobiology. 4 (5): 685–96. doi:10.1093/glycob/4.5.685. PMID7881183.
^Xu T, Bianco P, Fisher LW, Longenecker G, Smith E, Goldstein S, Bonadio J, Boskey A, Heegaard AM, Sommer B, Satomura K, Dominguez P, Zhao C, Kulkarni AB, Robey PG, Young MF (September 1998). "Targeted disruption of the biglycan gene leads to an osteoporosis-like phenotype in mice". Nature Genetics. 20 (1): 78–82. doi:10.1038/1746. PMID9731537.
^Pogány G, Hernandez DJ, Vogel KG (August 1994). "The in vitro interaction of proteoglycans with type I collagen is modulated by phosphate". Archives of Biochemistry and Biophysics. 313 (1): 102–11. doi:10.1006/abbi.1994.1365. PMID8053669.
^Vynios DH, Papageorgakopoulou N, Sazakli H, Tsiganos CP (September 2001). "The interactions of cartilage proteoglycans with collagens are determined by their structures". Biochimie. 83 (9): 899–906. doi:10.1016/S0300-9084(01)01332-3. PMID11698112.