The alphabet of intrinsic disorder: II. Various roles of glutamic acid in ordered and intrinsically disordered proteins

Uversky, Vladimir N

Bone phosphoproteins. Bone sialoprotein II (BSP II) is an important component of the bone mineralized matrix. This bone-specific glycoprotein contains phosphoserine and sulphotyrosine residues and two regions of contiguous glutamic acid residues (residues 77-84 and 156-169) . In one of the first studies dedicated to the analysis of bone phosphoprotein it has been shown that this glycoprotein can be purified from the mixture of proteins extracted by demineralization of rat bone with 0.5 M EDTA in 4 M guanidinium chloride. 197 It was also emphasized that this protein possessed an abnormal electrophoretic mobility This protein was shown to be involved in sensing infertile nutrient conditions in infected cells to promote a transfer from saprophytic to dormant microsclerotia for long-term survival. 213 VdGARP1 is a short (91 residues) extremely acidic protein with a pI of 3.3 that contains 52.8% negatively charged residues (31 glutamic acids and 17 aspartic acids).