The protein in glomerular basement membrane responsible for charge dependent filtration is -

Structure of glomerulus The glomerulus is composed of an anastomosing network of capillaries lined by fenestrated endothelium invested by two layers of epithelium. The visceral epithelium (podocytes) is incorporated into and becomes an intrinsic part of the capillary wall, separated from endothelial cells by basement membrane. The parietal epithelium, situated on Bowman's capsule, lines the urinary space. The glomerular capillary wall is the filtering membrane and consist of the following structures. A thin layer of fenestrated endothelial cells. Glomenilar basement membrane (GBM). Visceral epithelium (Podocytes) → their adjacent foot processes are separated by filtration slits. Mesangial matrix and mesangial cells support the entire glomerular tuft. Glomerular barrier function The filtration of any substance through glomerular filtration layer depends on two factors - A.  Size of the substance Glomerular filtration layer is more porous than another capillary membrane. Any neutral substance <4A diameter freely filters through this layer B.  The charge of the substance The acidic glycoprotein of the GBM and the acidic sialoglycoprotein of epithelial and endothelial cell coats are negatively charged (anionic). Therefore all anionic molecules (negatively charged) including albumin are repelled by the filtration layer. So, The larger the molecule → less permeable The more cationic the protein → more permeable