The catalytic activity of several proteolytic enzymes is altered by high concentrations of urea and guanidine salts (2-4). These studies, in conjunction with certain physical data, indicate that hydrogen bonding in the secondary structure of these enzymes is essential for maintenance of their catalytic function. Because of the increasing amount of information that is available concerning the st...

1. Proteoglycans were extracted from sclera with 4 M-guanidine hydrochloride in the presence of proteinase inhibitors and purified by ion-exchange chromatography and density-gradient centrifugation. 2. The entire proteoglycan pool was characterized by compositional analyses and by specific chemical (periodate oxidation) and enzymic (chondroitinases) degradations. The glycan moieties of the mole...

The Na+ content of poliovirus-infected HeLa S3 cells increased during the late phase of virus replication, after virus inhibition of host cell protein synthesis and in coincidence with late viral functions. Guanidine hydrochloride blocked the rise in Na+ content, whereas the antiguanidine agent choline fully reversed the guanidine block. Expression of one or more late viral functions was essent...

The subunit interactions of fumarase have been examined as a function of enzyme concentration, pH, and concentration of guanidine hydrochloride. Fumarase was found to dissociate, with loss of activity, either at low concentrations of the enzyme ( 1 M). At pH 9 a species of enzyme was produced which was ...

Class A beta-lactamases of the TEM family contain a single disulphide bond which connects cysteine residues 77 and 123. To clarify the possible role of the disulphide bond in the stability and folding kinetics of the TEM-1 beta-lactamase, this bond was removed by introducing a Cys-77-->Ser mutation, and the enzymically active mutant protein was studied by reversible guanidine hydrochloride-indu...

The unfolding and dissociation of the dimeric enzyme aspartate aminotransferase (D) from Escherichia coli by guanidine hydrochloride have been investigated at equilibrium. The overall process was reversible, as judged from almost complete recovery of enzymic activity after dialysis of 0.7 mg of denatured protein/mL against buffer. Unfolding and dissociation were monitored by circular dichroism ...

Hydrodynamic, chemical, and optical properties of arginine deiminase (EC 3.5.3.6) from Mycoplasma arthritidis are reported for the enzyme isolated from log phase cells. The s& +, and D’& values of the enzyme are 5.48 S and 5.87 x 10V7 cm’/s, respectively; the molecular weight is 87,300. Determination of the amino acid composition shows that about 45% of the residues are nonpolar. Another unique...

The results of a study the wound healing activity composition based on hydrogel polyhexamethylene guanidine hydrochloride and Bergenia crassifolia extract, under conditions modeling thermal burns in laboratory animals (rats), are presented. It was found that affects change summary antioxidant leukocyte towards normalization these indicators. Morphological analysis slices showed that, influence ...