Table 1.

Heparan sulfate proteoglycans

Class	Proteoglycan	Core mass (kDa)a	Chain type (number)b	Tissue	Human disease
Membrane-bound	Syndecan-1–syndecan-4	31–45	HS (2–3) in Sdc2 and Sdc4; HS/CS (3–4 HS/1-2 CS) in Sdc1 and Sdc3	Epithelial cells, fibroblasts
	Glypican-1–glypican-6	57–69	HS (1–3)	Epithelial cells, fibroblasts	Simpson–Golabi–Behmel syndrome (overgrowth) (GPC3) (Pilia et al. 1996); omodysplasia (skeletal dysplasia) (GPC6) (Campos-Xavier et al. 2009)
	Betaglycan (part-time PG)	110	HS/CS (1–2)	Fibroblasts
	Neuropilin-1 (part-time PG)	130	HS or CS (1)	Endothelial cells
	CD44v3	37	HS (1)	Lymphocytes
Secretory vesicles	Serglycin	10–19	Heparin/CS (10–15)	Mast cells, hematopoietic cells
Extracellular matrix	Perlecan	400	HS (1–4)	Basement membranes	Schwartz–Jampel syndrome (skeletal dysplasia) (Nicole 2000; Arikawa-Hirasawa et al. 2001)
	Agrin	212	HS (2–3)	Basement membranes
	Collagen XVIII	150	HS (1–3)	Epithelial cells, basement membranes	Knobloch syndrome type I (Sertie et al. 2000)

HS, heparan sulfate; CS, chondroitin sulfate; PG, proteoglycan.

^aThe variation in core mass is because of species differences.

^bThe number of chains is based on the number of putative attachment sites for chain initiation as well as data from the literature; the actual number of chains varies by method, tissue, and species.