Negatively charged polymers protect antinuclear antibody against inactivation by acylating agents.

For many practical applications, monoclonal antibodies must be chemically modified without any significant loss in their immunoreactivity. In some situations, however, the amino acid residue crucial for antibody activity may be highly reactive toward the modifying agent, which results in antibody inactivation. The method to prevent inactivation of a modification-sensitive antinuclear monoclonal antibody by acylating agents was developed.

p-Nitrophenylcarbonyl-PEG-PE-liposomes: fast and simple attachment of specific ligands, including monoclonal antibodies, to distal ends of PEG chains via p-nitrophenylcarbonyl groups.

We have attempted to simplify the procedure for coupling various ligands to distal ends of liposome-grafted polyethylene glycol (PEG) chains and to make it applicable for single-step binding of a large variety of a primary amino group-containing substances, including proteins and small molecules. With this in mind, we have introduced a new amphiphilic PEG derivative, p-nitrophenylcarbonyl-PEG-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (pNP-PEG-DOPE), synthesized by reaction of DOPE with excess of bis(p-nitrophenylcarbonyl)-PEG in a chloroform/triethylamine mixture. pNP-PEG-DOPE readily incorporates into liposomes via its PE residue, and easily binds primary amino group-containing ligands via its water-exposed pNP groups, forming stable and non-toxic urethane (carbamate) bonds.

A new approach to preparative enzymatic synthesis. Reprinted from Biotechnology and Bioengineering, Vol. XIX, No. 9, Pages 1351-1361.

A new approach to preparative organic synthesis in aqueous-organic systems is suggested. It is based on the idea that the enzymatic process is carried out in a biphasic system "water-water-immiscible organic solvent." Thereby the enzyme is localized in the aqueous phase-this eliminates the traditional problem of stabilizing the enzymes against inactivation by a nonaqueous solvent.

Effects of protein kinase C inhibitors on thromboxane production by thrombin-stimulated platelets.

The purpose of these studies was to identify a possible role for protein kinase C in thromboxane production. The effects of four putative protein kinase C inhibitors were studied with platelet stimulation by thrombin (0.5-150 nM), Thrombin Quick I (1.