Blood inhibitory capacity toward exogenous plasmin.

Stabilized, active plasmin is a novel thrombolytic for direct delivery to clots. Although it is known that protease inhibitors in plasma inhibit plasmin, the amount of plasmin that can be added to plasma/blood before free plasmin is observed is not clear. Determination of free plasmin activity in plasma using chromogenic substrates represents a challenge due to false-positive signals from plasmin entrapped by alpha2-macroglobulin.

The properties of rabbit alpha1-macroglobulin upon activation are distinct from those of rabbit and human alpha2-macroglobulins.

We have characterized native and activated forms of rabbit alpha1M and compared them to rabbit and human alpha2M. Similar to human alpha2M, rabbit alpha1M is a tetramer associated via disulfide bonds and non-covalent interactions that exhibits autolysis into two fragments when heated. Like human alpha2M, rabbit alpha1M is cleaved by trypsin at one site; however, rabbit alpha1M shares characteristics with rabbit alpha2M that are different from the properties of human alpha2M.

The C-terminal domains of the gingipain K polyprotein are necessary for assembly of the active enzyme and expression of associated activities.

The Porphyromonas gingivalis lysine-specific cysteine protease (gingipain K, Kgp) is expressed as a large precursor protein consisting of a leader sequence, a pro-fragment, a catalytic domain with a C-terminal IgG-like subdomain (IgSF) and a large haemagglutinin/adhesion (HA) domain. In order to directly study the role of these non-catalytic domains in pro-Kgp processing and maturation in P. gingivalis, the wild-type form of the gene was replaced with deletion variants encoding C-terminally truncated proteins, including KgpDeltaHA3/4 (Delta1292-1732 aa), KgpDeltaHA2-4 (Delta1157-1732 aa), KgpDeltaHA1-4 (Delta738-1732 aa), KgpDeltaC-term/HA (Delta681-1732 aa) and KgpDeltaIg/C-term/HA (602-1732 aa).

Growth phase-dependent production of a cell wall-associated elastinolytic cysteine proteinase by Staphylococcus epidermidis.

Staphylococcus epidermidis, a Gram-positive, coagulase-negative bacterium is a predominant inhabitant of human skin and mucous membranes. Recently, however, it has become one of the most important agents of hospital-acquired bacteriemia, as it has been found to be responsible for surgical wound infections developed in individuals with indwelling catheters or prosthetic devices, as well as in immunosupressed or neutropenic patients. Despite their medical significance, little is known about proteolytic enzymes of S.

Proteolysis of interleukin-6 receptor (IL-6R) by Porphyromonas gingivalis cysteine proteinases (gingipains) inhibits interleukin-6-mediated cell activation.

Current consensus is that periodontitis is an infectious disease in which a deregulated chronic inflammatory reaction not only may lead to periodontal tissue damage but also eventually may cause tooth loss. In controlling the inflammatory state the interplay between a network of cytokines and their receptors plays an important role. Here we show that the interleukin-6 receptor (IL-6R) is rapidly and efficiently inactivated by gingipains, the arginine- (HRgpA and RgpB) and lysine- (Kgp) specific cysteine proteinases from Porphyromonas gingivalis.

Isolation and properties of stachyrase A, a chymotrypsin-like serine proteinase from Stachybotrys chartarum.

A strain of the common mold Stachybotrys chartarum has been isolated from the lung of a child with pulmonary hemorrhage. We report the purification of stachyrase A, a new serine chymotrypsin-like proteinase from S. chartarum.