We have previously shown that lactoperoxidase (LPO) covalently coupled to polystyrene tissue culture flasks can be used to radioiodinate monolayer cell proteins that come into intimate contact with the LPO-polystyrene surface. These studies have now been extended to include a detailed examination of the class of iodinated polypeptides migrating with apparent molecular weights of 50,000 and 55,0...

Phycobilisomes, the light-harvesting complexes of cyanobacteria and red algae, contain two to four types of chromophores that are attached covalently to seven or more members of a family of homologous proteins, each carrying one to four binding sites. Chromophore binding to apoproteins is catalyzed by lyases, of which only few have been characterized in detail. The situation is complicated by n...

Cytochromes c are metalloproteins that function in electron transfer reactions and contain a heme moiety covalently attached via thioether linkages between the co-factor and a CXXCH motif in the protein. Covalent attachment of the heme group occurs on the positive side of all energy-transducing membranes (bacterial periplasm, mitochondrial intermembrane space and thylakoid lumen) and requires m...

In central nervous system (CNS)-directed gene therapy, efficient targeting of brain parenchyma through the vascular route is prevented by the endothelium and the epithelium of the blood-brain and the blood-cerebrospinal fluid barriers, respectively. In this study, we evaluated the feasibility of the combined genetic and chemical adenovirus capsid modification technology to enable transcellular ...

We have raised antisera against human prothrombin activation fragment Fa in rabbits and have chromatographed the respective immunoglobulin G fractions on prothrombin-Sepharose, Prl-Sepharose, and FZ-Sepharose immunoadsorbents. The specific antibody population obtained was utilized to construct a double antibody radioimmunoassay capable of measuring as little as 0.8 rig/ml of this component. Our...

A gene encoding an alditol oxidase was found in the genome of Streptomyces coelicolor A3(2). This newly identified oxidase, AldO, was expressed at extremely high levels in Escherichia coli when fused to maltose-binding protein. AldO is a soluble monomeric flavoprotein with subunits of 45.1 kDa, each containing a covalently bound FAD cofactor. From sequence alignments with other flavoprotein oxi...

Typically, the redox proteins of respiratory chains in Gram-negative bacteria are localized in the cytoplasmic membrane or in the periplasm. An alternative arrangement appears to be widespread within the betaproteobacterial genus Neisseria, wherein several redox proteins are covalently associated with the outer membrane. In the present paper, we discuss the structural properties of these outer ...

We have raised antisera against human prothrombin activation fragment F2 in rabbits and have chromatographed the respective immunoglobulin G fractions on prothrombin-Sepharose, Pr1-Sepharose, and F2-Sepharose immunoadsorbents. The specific antibody population obtained was utilized to construct a double antibody radioimmunoassay capable of measuring as little as 0.8 ng/ml of this component. Our ...

The electron beam induced functionalization of graphene through the formation of covalent bonds between free radicals of polyaromatic molecules and C=C bonds of pristine graphene surface has been explored using first principles calculations and high-resolution transmission electron microscopy. We show that the energetically strongest attachment of the radicals occurs along the armchair directio...

We have covalently modified the recA protein from Escherichia coli with the photoaffinity ATP analog 8-azido-[alpha-32P]ATP (N3-ATP). Covalent attachment of N3-ATP to recA protein is dependent on native protein conformation and is shown to be specific for the site of ATP hydrolysis by the following criteria. (i) Binding of the probe to recA protein is inhibited by ATP and competitive inhibitors...