An account of x-ray crystallographic studies of monoclinic porcine pepsin crystals is presented. The chain fold specific for aspartyl proteases is described in detail. As the results of 2-A refinement have shown, the actual structure is that of ethanol-inhibited pepsin. The structure, although close to those of fungal aspartyl proteases, has some specific features: one of them is an insertion n...

The procedure generally used for the isolation of extracellular, cell-associated proteinases of Lactococcus lactis species is based on the release of the proteinases by repeated incubation and washing of the cells in a Ca-free buffer. For L. lactis subsp. cremoris Wg2, as many as five incubations for 30 min at 29 degrees C are needed in order to liberate 95% of the proteinase. Proteinase releas...

A method is described that allows the in vivo differentiation of N-acetyl aspartate (NAA) from N-acetyl aspartyl glutamate (NAAG) by in vivo MR spectroscopy (MRS) at 3 Tesla (3T). The method, which is based on MEGA-point-resolved spectroscopy (PRESS) editing, selectively targets the aspartyl spin system of one species while deliberately removing the other species from the spectrum. This allows ...

We have purified and characterized a neutral proteinase activity from pig uterine myometrium. The proteinase co-purified with the actomyosin complex and could only be separated from it by a high concentration of a chaotropic ion, 3M-NaBr. The proteinase was further purified by gel filtration and affinity chromatography. The purified protein showed a single band on sodium dodecyl sulphate/polyac...

To determine the location of the proteinase in the covalent serpin-proteinase complex we prepared seven single-cysteine-containing variants of the Pittsburgh variant of the serpin a1-proteinase inhibitor, and we labeled each cysteine with the dansyl f luorophore. The dansyl probes were used to determine proximity of the proteinase trypsin in covalent and noncovalent complexes with the serpin, b...

The gene encoding the cell-envelope-associated proteinase of Lactobacillus paracasei subsp. paracasei NCDO 151 (formerly Lactobacillus casei NCDO 151) was cloned and sequenced. The gene was located on the chromosome and encoded a polypeptide of 1902 amino acids. The proteinase is N-terminally cleaved upon maturation. It shows extensive homology to the Lactococcus lactis subsp. cremoris Wg2 prot...

Pseudomonas fluorescens P1 is a psychrotrophic bacterium isolated from milk. Proteinase P1, the main extracellular heat-stable proteinase fraction of P. fluorescens P1, has been purified to homogeneity. A procedure with a sandwich enzyme-linked immunosorbent assay, using microplates and alkaline phosphatase conjugate was shown to detect 0.25 ng of proteinase P1 in 1 ml of reconstituted skim mil...