Extracellular carboxylic ester hydrolases are produced by many bacterial pathogens and have been shown recently to be important for virulence of some pathogens. However, these hydrolases are poorly characterized in enzymatic activity. This study prepared and characterized the secreted ester hydrolase of Streptococcus equi ssp. equi (designated SeE for S. equi esterase). SeE hydrolyzes ethyl ace...

Adsorptive pinocytosis of acid hydrolases by fibroblasts depends on phosphomannosyl recognition markers on the enzymes and high-affinity pinocytosis receptors on the cell surface. In this study, beta-glucuronidase binding to the cell surface of attached fibroblasts was found to be saturable and inhibitable by mannose-6-phosphate (Man-6-P). Dissociation of cell-bound beta-glucuronidase occurred ...

Populations of Chinese hamster ovary cells selected for resistance to diphtheria toxin were found to be highly enriched for mutants deficient in the uptake of lysosomal hydrolases via the mannose 6-phosphate receptor. One doubly defective mutant, DTF 1-5-1, exhibited increased resistance to Sindbis virus, although it was able to bind and internalize virus normally. Normal production of virus wa...

The subcellular distribution of various lysosomal hydrolases and mitochondria! cytochrome c oxidase of mammary carcinomas of C3H mice was studied by means of differential centrifugation and zonal ultracentriftigation and in electron histochemical preparations. Tumors that received a single local dose of 500, 1000, or 7000 rad showed an increase in the specific activities of acid hydrolases in t...

The subcellular distribution of various lysosomal hydrolases and mitochondria! cytochrome c oxidase of mammary carcinomas of C3H mice was studied by means of differential centrifugation and zonal ultracentriftigation and in electron histochemical preparations. Tumors that received a single local dose of 500, 1000, or 7000 rad showed an increase in the specific activities of acid hydrolases in t...

Arabidopsis thaliana contains multiple carboxyesterases (AtCXEs) with activities toward xenobiotics, including herbicide esters that are activated to their phytotoxic acids upon hydrolysis. On the basis of their susceptibility to inhibition by organophosphates, these AtCXEs are all serine hydrolases. Using a trifunctional probe (TriFP) bearing a fluorophosphonate together with biotin and rhodam...

HIT (histidine triad) proteins, named for a motif related to the sequence HphiHphiHphiphi (phi, a hydrophobic amino acid), are a superfamily of nucleotide hydrolases and transferases, which act on the alpha-phosphate of ribonucleotides, and contain a approximately 30 kDa domain that is typically either a homodimer of approximately 15 kDa polypeptides with two active-sites or an internally, impe...