Osseointegration is the structural and functional connection between bone tissues and implants such as titanium dioxide (TiO2). The bone-TiO2 interface is thought to contain proteoglycans. However, exhaustive analysis of the proteins in this layer has not been performed. In this study, we evaluated the bone protein adhered on the surface of TiO2 comprehensively. Pig bone protein was extracted b...

An important factor complicating the recovery of recombinant proteins from Escherichia coli is their intracellular location. An alternative to the commonly used method of releasing these proteins by mechanical disruption is to chemically permeabilize the cells. The objective of this research was to characterize the protein release kinetics of a permeabilization process using guanidine-HCl and T...

Contributions of tyrosyl residues to trypsinand chymotrypsin-inhibitory activities in two homologous proteinase inhibitors were investigated by modifying them with N-acetylimidazole under various conditions. In Bowman-Birk soybean proteinase inhibitor, Tyr 55, immediately following the antichymotryptic site, Leu 53-Ser 54, is relatively inaccessible to N-acetylimidazole and can only be acetylat...

In previous work in our laboratory, 12 guanidine-resistant (gr) mutants of poliovirus were selected from 12 separate stocks of plaque-purified guanidine-sensitive (gs) viruses (K. Anderson-Sillman, S. Bartal, and D. R. Tershak, J. Virol. 50:922-928, 1984). Peptide mapping of protein 2C and evaluation of virus growth at different temperatures enabled us to subdivide these mutants into several di...

Amiloride, a diuretic used in the treatment of hypertension and congestive heart failure, and 2-guanidine-4-methylquinazoline (GMQ) are guanidine compounds that modulate acid-sensing ion channels. Both compounds have demonstrated affinity for a variety of membrane proteins, including members of the Cysloop family of ligand-gated ion channels, such as the heteromeric GABA-A abg receptors. The ac...

The denaturation of certain proteins is characterized in part by the appearance of titratable sulfhydryl groups (8,11, 13).’ Moreover, the proportion of these groups which appears in any one protein is dependent upon the method of denaturation employed (3,5,6). Proteins dissolved in solutions of urea, guanidine hydrochloride, and related substances show widely different amounts of sulfhydryl gr...

The influence of protein conformation upon the circular dichroism (CD) bands of two peroxidase isoenzymes (Al and C) was investigated by using guanidine hydrochloride and other denaturing agents. In all four proteins, guanidine hydrochloride markedly reduces the Zl-nm CD band, indicating disruption of the ordered peptide backbone conformation. Similarly guanidine hydrochloride greatly diminishe...

The active site of [NiFe] hydrogenases contains a strictly conserved arginine that suspends a guanidine nitrogen atom <4.5 Å above the nickel and iron atoms. The guanidine headgroup interacts with the side chains of two conserved aspartic acid residues to complete an outer-shell canopy that has thus far proved intractable to investigation by site-directed mutagenesis. Using hydrogenase-1 from E...

Fibrin, when formed from purified fibrinogen and thrombin, with the exclusion of either calcium or an unidentified serum factor (or both), can be dissolved in several rather mild reagents. Dissolution has been reported in dilute acid (1) and in moderately concentrated solutions of urea (2-5), guanidine hydrochloride (2-5), and histamine dihydrochloride (5). In urea, the dissolved particles have...

Trace levels of pharmaceuticals have been detected in surface water and may pose a health risk to humans and other organisms. New chromatographic materials will help identify and quantify these contaminants. We introduce a new ion chromatographic (IC) material designed to separate cationic pharmaceuticals and report its ability to separate a group of guanidine compounds. Guanidine moieties are ...