Search results for "histidine-rich"
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A Comparative Study on Nickel Binding to Hpn-like Polypeptides from Two Helicobacter pylori Strains
2021
Combined potentiometric titration and isothermal titration calorimetry (ITC) methods were used to study the interactions of nickel(II) ions with the N-terminal fragments and histidine-rich fragments of Hpn-like protein from two Helicobacter pylori strains (11637 and 26695). The ITC measurements were performed at various temperatures and buffers in order to extract proton-independent reaction enthalpies of nickel binding to each of the studied protein fragments. We bring up the problem of ITC results of nickel binding to the Hpn-like protein being not always compatible with those from potentiometry and MS regarding the stoichiometry and affinity. The roles of the ATCUN motif and multiple His…
Histidine-rich glycoprotein-induced vascular normalization improves EPR-mediated drug targeting to and into tumors
2018
Tumors are characterized by leaky blood vessels, and by an abnormal and heterogeneous vascular network. These pathophysiological characteristics contribute to the enhanced permeability and retention (EPR) effect, which is one of the key rationales for developing tumor-targeted drug delivery systems. Vessel abnormality and heterogeneity, however, which typically result from excessive pro-angiogenic signaling, can also hinder efficient drug delivery to and into tumors. Using histidine-rich glycoprotein (HRG) knockout and wild type mice, and HRG-overexpressing and normal t241 fibrosarcoma cells, we evaluated the effect of genetically induced and macrophage-mediated vascular normalization on th…
Human histidine-rich glycoprotein expressed in SF9 insect cells inhibits apatite formation
1997
Histidine-rich glycoprotein (HRG) is structurally related to the alpha2-HS glycoprotein/fetuin family of mammalian plasma proteins; both belong to the cystatin superfamily of proteins. We expressed recombinant human HRG and alpha2-HS in Sf9 insect cells for functional analysis. Recombinant HRG bound heparin and fibrinogen while alpha2-HS did not. Both proteins inhibited the formation of apatite, recombinant HRG (IC50 approximately 1 microM) with 2-fold lower molar activity than alpha2-HS (IC50 approximately 0.5 microM). The inhibition in vitro of apatite formation suggests a new function for plasma HRG protein, inhibition of phase separation in blood vessels.