We have used lactoperoxidase-catalyzed iodination to study the topographical distribution of proteins in free and membrane-bound polysomes and in isolated ribosomal subunits. Free polysomes or rough microsomes were iodinated with 125I and then dissociated into 40 S and 60 S subunits by the use of puromycin/KCl. The separated subunits were iodinated with 13’1 and their protein composition analyz...

Lactoperoxidase is a member of the family of the mammalian heme peroxidases which have a broad spectrum of activity. Their best known effect is their antimicrobial activity that arouses much interest in in vivo and in vitro applications. In this context, the proper use of lactoperoxidase needs a good understanding of its mode of action, of the factors that favor or limit its activity, and of th...

Investigation of bovine lacrimal and harderian glands revealed the presence of the enzyme lactoperoxidase, which was isolated and purified. A nonheme, iron-containing protein was identified at the same time. Both proteins are present in milk, mammary glands, and salivary glands. Their roles are discussed: The lactoperoxidase may be important in controlling bacterial flora.

Glutathione (GSH) was oxidized to GSSG in the presence of H2O2, tyrosine, and peroxidase. During the GSH oxidation catalyzed by lactoperoxidase, O2 was consumed and the formation of glutathione free radical was confirmed by ESR of its 5,5'-dimethyl-1-pyrroline-N-oxide adduct. When lactoperoxidase was replaced by thyroid peroxidase in the reaction system, the consumption of O2 and the formation ...

Peroxidases are abundant in nature, and the primary function of mammalian peroxidases is to catalyze the peroxidation of halides and pseudohalides. Previous studies have shown that antibodies raised against bovine lactoperoxidase moderately cross-react with human salivary peroxidase, a feature that has been used in the present study to examine epitopes common to the antigen and human salivary p...

background: lactoperoxidase (lpo) is one of the most heat-stable enzymes in milk and its inactivation has been proposed for monitoring thermal processes. the aim of this study was to provide information on activity and thermal inactivation behavior of lpo in iranian cow and buffalo milk and whey. methods: sixty cow and buffalo milk samples were collected. the lpo activity was measured using spe...

lzSI-labelling of external proteins with lactoperoxidase has been widely used as a probe of membrane structure. We have applied this technique to the sarcoplasmic reticulum from rabbit skeletal muscle isolated by differential centrifugation, and have compared the labelling of membrane components using free and immobilized lactoperoxidase. The major proteins in the sarcoplasmic reticulum are the...

Membrane-associated immunoglobulin (M-Ig) was isolated from Daudi cells which had been radioiodinated using lactoperoxidase. This M-Ig was found to have a molecular size on SDS-PAGE of 330,000 daltons. The component protein chains (micro and K) have molecular sizes of 75,000 and 33,000 daltons, respectively. Further studies showed that [(3)H]galactose can be incorporated into K-chains, but that...