Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Binding of 125I-labelled fibronectin and vitronectin to streptococci of group A (S. pyogenes), group B (S. agalactiae) and group C (S. dysgalactiae and S. zooepidemicus) isolated from various human infections and bovine mastitis, and S. uberis bovine isolates, was studied. Binding of vitronectin and fibronectin was common among both human groups A and C, and bovine group C streptococci. S. agalactiae strains of human and bovine origin as well as S. uberis bovine isolates bound low levels of both proteins. The binding of radiolabelled fibronectin and vitronectin to selected groups A and C streptococcal strains was specific, time-dependent and occurred with both live and heat-killed (80 degrees C for 15 min) cells. Binding declined rapidly after treatment of cells with trypsin or proteinase K, while pepsin digestion at pH 5.5 affected vitronectin but not fibronectin binding.
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PMID:Comparative studies on binding of vitronectin and fibronectin to groups A and C streptococci. 128 49

Treponema denticola surface proteins were studied for their biochemical and biological characteristics. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of detergent extracts of whole cells revealed a major protein of 53 kDa and a number of minor proteins. Antiserum raised against whole cells of T. denticola ATCC 35405 reacted with the 53-kDa protein and a 72-kDa protein but not with the other proteins. Immunoelectron microscopy with anti-53-kDa-protein antibodies showed that the 53-kDa protein is located on the surface of the cell. SDS-PAGE analysis of unheated samples indicated that the 53-kDa protein is the major component of oligomers with molecular masses ranging from 130 to 300 kDa. Western blot (immunoblot) analysis showed that the high-molecular-mass oligomers reacted with whole-cell antiserum and anti-53-kDa-protein antibody. The aggregates dissociated into their subunits after heating to 70 degrees C. Isoelectric focusing followed by SDS-PAGE indicated that the 53-kDa protein was separated into several forms with apparent pI values ranging from 8.0 to 5.5. The oligomeric forms were highly resistant to proteolysis by trypsin and proteinase K, whereas the monomeric proteins were readily digested. A clone expressing a 53-kDa antigen in Escherichia coli was isolated from a lambda ZAP II DNA library of T. denticola ATCC 35405. The recombinant protein had exactly the same molecular mass as the major 53-kDa T. denticola surface protein and reacted with antisera raised against this protein. The role of T. denticola ATCC 35405 surface proteins in attachment to laminin, fibronectin, gelatin, fibrinogen, and bovine serum albumin (BSA) was studied by a modified Western blot binding assay. Fibronectin, laminin, and fibrinogen attached to the 53-kDa surface protein of T. denticola as well as to a 72-kDa protein, whereas no attachment to gelatin or BSA was observed. Attachment could be inhibited by pretreating the blots with fibrinogen but not with gelatin or BSA. Our results suggest that the 53-kDa major surface protein of T. denticola may play a role in the attachment to host proteins and may thus be an important virulence determinant of this species.
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PMID:Characterization, cloning, and binding properties of the major 53-kilodalton Treponema denticola surface antigen. 156 96

The ability of 16 isolates of the human gastroduodenal pathogen Helicobacter pylori to bind 125I-radiolabelled tissue proteins was quantitated by liquid-phase assay. While capable of binding generally low levels of collagen types I and II, vitronectin, and fibronectin (average binding, 8%; highest binding, 23%), the various H. pylori isolates were good binders of the basement membrane proteins collagen type IV and laminin (average binding, 27%; highest binding, 60%). Campylobacter species tested bound lower levels of collagen type IV and laminin (average binding, 12%; highest binding, 17%). Trypsin and proteinase K treatment of H. pylori cells markedly reduced the binding of collagen type IV and laminin, as did heat treatment, suggesting that the binding of basement membrane proteins is mediated by bacterial surface proteins. Binding of both basement membrane proteins was rapid and saturable. 125I-collagen type IV binding to H. pylori 915 was inhibited by preincubation with unlabelled collagen type IV but was not inhibited by laminin or a number of other proteins. Once bound, radiolabelled collagen type IV but was not displaced by an excess of unlabelled collagen type IV, indicating that the binding interaction was of high affinity. Binding of laminin was partially reversible, and analysis in a solid-phase nonradiolabel assay showed that the interaction was of high affinity, with a Kd of 7.9 nM. This interaction was affected by salt, indicating the presence of a hydrophobic component in the ability of H. pylori to bind laminin.
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PMID:High-affinity binding of the basement membrane proteins collagen type IV and laminin to the gastric pathogen Helicobacter pylori. 193 98

The adherence of Treponema denticola GM-1, TD-4, and MS25 to human gingival fibroblasts (HGFs) was studied to serve as an introduction to investigations into the interactions of these oral bacteria with human host cells. Under both aerobic (5% CO2) and anaerobic (85% N2 plus 10% H2 plus 5% CO2) environments, the interactions with the HGFs were such that strains GM-1 and MS25 were consistently more adherent than strain TD-4. Polyclonal antibodies to GM-1 inhibited GM-1 adherence by 70%, while MS25 and TD-4 showed differing degrees of cross-reactive inhibition, indicative of common but not identical epitopes on the surface of the three T. denticola strains. Pretreatment of the three strains with trypsin did not inhibit adherence; proteinase K did, however, inhibit this interaction by 80%. Trypsin pretreatment of the HGFs resulted in increases in adherence of 50 and 86% for GM-1 and MS25, respectively, while a decrease of 41% was noted for TD-4. Exposure of the T. denticola strains to sugars and lectin pretreatment of the HGFs implicated adherence mediation by mannose and galactose residues on the HGF surface. Periodate treatment of HGFs resulted in a 50% drop in adherence for GM-1 and MS25, but did not decrease that of TD-4. Addition of fetal bovine serum inhibited adherence of the three strains to differing degrees, with TD-4 being the most susceptible. Addition of purified fibronectin (100 micrograms/ml) resulted in greater than 50% inhibition in GM-1 and MS25 adherence, while a 25% increase occurred with TD-4. While strain differences were noted in some of the parameters studied, the results indicate two possibilities for T. denticola-HGF adherence: a lectinlike adhesin(s) on the T. denticola surface with affinity for galactose and mannose on the HGF surface, and a serum host factor(s) bridging T. denticola and HGFs.
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PMID:Interaction of Treponema denticola TD-4, GM-1, and MS25 with human gingival fibroblasts. 216 Apr 30

In allergic and nonallergic lung diseases, if intraluminal mast cells adhere to airway epithelium, inflammatory mediators released from activated mast cells may reach high local concentrations and thus greatly affect airway function. To determine whether mast cells adhere to airway epithelial cells, radiolabeled or unlabeled dog mastocytoma cells were incubated with cultured dog tracheal epithelial cells, with extracellular matrix substrates, and with cryostat-cut sections of dog trachea. Mast cells adhered well to cultured epithelial cells (35 +/- 13% adhesion, mean +/- 1 SD, n = 23) but adhered poorly to types I and IV collagen or to fibronectin (less than 7.5% mean adhesion in all cases). Similarly, in tracheal tissue sections, mast cells adhered preferentially to epithelial cells in surface epithelium or in submucosal glands but not to basal membrane or connective tissue. Adhesion to cultured epithelial cells was a characteristics of a subpopulation of mast cells, could persist for more than 48 h, did not require energy or the presence of divalent cations, and was not mediated by a known family of leukocyte-associated adhesion glycoproteins. Adhesion was completely abolished by pretreatment of mast cells with pronase E or proteinase K but not with trypsin (up to 10 micrograms/ml at 37 degrees C for 20 min each). In contrast, pretreatment of cultured epithelial cells with any of these proteinases had no effect on adhesion. It is concluded that dog mastocytoma mast cells adhere to dog tracheal epithelial cells and do so selectively. It is suggested that mast cell adhesion to airway epithelium may play a role in the effectiveness of mast cell-epithelial cell interactions, and thus, in certain lung diseases, airway function may be affected by intraluminal mast cells more than is currently appreciated.
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PMID:Selective adhesion of mast cells to tracheal epithelial cells in vitro. 245 Sep 14

Proteases have been used as a tool to investigate the role of surface molecules in fibronectin-mediated cell adhesion. Proteolytic digestion of membrane-proteins by pronase (1 mg/ml for 20 min at 37 degrees C) completely inhibited adhesion of baby hamster kidney (BHK) fibroblasts on fibronectin-coated plastic dishes. Various degrees of inhibition were also obtained after treatment with proteinase K, chymotrypsin, papain, subtilopeptidase A, and thermolysin. Protein synthesis was required to restore the adhesive properties of pronase-treated cells, showing the protein nature of the molecules involved in adhesion to fibronectin. A peculiar feature of these proteins was their resistance to cleavage by trypsin. After prolonged trypsin treatment (1 mg/ml for 20 min at 37 degrees C), cells adhered and spread on fibronectin-coated dishes, even when protein synthesis was inhibited by 4 microM cycloheximide. Under these conditions only three glycoproteins (gp) of molecular weight 130,000, 120,000, and 80,000 were left on the cell surface. These were precipitated by a rabbit antiserum against BHK cells that also inhibited adhesion of trypsin-treated cells. gp120 and gp80 were left at the cell surface after mild pronase digestion (0.2 mg/ml for 20 min at 37 degrees C), under conditions not affecting adhesion. These data suggest that these glycoproteins may be involved in fibronectin-mediated cell adhesion in some yet unknown way.
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PMID:Cell surface molecules and fibronectin-mediated cell adhesion: effect of proteolytic digestion of membrane proteins. 674 66

Binding of outer membrane (OM) preparations of the thermophilic Campylobacter species C. jejuni to epithelial cell membranes and extracellular matrix proteins were studied in an in vitro model system using enzyme-linked immunosorbent assay. The OM preparations exhibited significant binding to INT 407 intestinal cell membranes. The process of adhesion was modulated by enzymatic, chemical or immunological pretreatment of the bacteria. Following oxidation of the lipopolysaccharide (LPS) with sodium meta-periodate, the OM preparations essentially retained their binding properties. After pretreatment with proteinase K, the OM preparations lost their binding capacity and the apparent molecular mass of the major OM protein shifted from 42 to 24 kDa. Preincubation of C. jejuni bacteria with C. jejuni-specific antiserum reduced adhesion significantly; preincubation with LPS-specific monoclonal antibodies only to a minimal extent. The OM preparations also bound significantly to the extracellular matrix proteins collagen and fibronectin; however, they bound virtually no bovine serum albumin or horse serum.
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PMID:Binding of outer membrane preparations of Campylobacter jejuni to INT 457 cell membranes and extracellular matrix proteins. 857 16

The ability of Prevotella intermedia to bind type I collagen was investigated. A simple method in which bacterial cells were allowed to attach to collagen-coated microtitre plate wells was used to characterize the activity. All strains of P. intermedia tested, as well as those of the closely related species Prevotella nigrescens, showed a capacity to attach to the collagen film. Exponential-phase cultures of P. intermedia demonstrated a greater binding capacity than older cells. Attachment to the collagen film was inhibited by the presence of EDTA, type I and IV collagen, denatured collagen (gelatin), fibrinogen or fibronectin. Pretreatment of bacterial cells with heat (60 degrees C, 30 min) or proteinase K also inhibited the binding. The collagen-binding activity could be solubilized from the bacterial cell surface by incubation with Zwittergent 3-14, a zwitterionic detergent. The collagen-binding capacity of P. intermedia demonstrated in the present study represents a mechanism of colonization allowing these bacteria to attach to a tissue matrix.
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PMID:Collagen-binding activity of Prevotella intermedia measured by a microtitre plate adherence assay. 870 94

Cell surface hydrophobicity of Campylobacter jejuni, C. coli, C. lari and C. upsaliensis was tested by hydrophobic interaction chromatography on octylsepharose CL-4B. The hydrophobicity was influenced by cultivation mode, presence or absence of intact lipopolysaccharide (LPS) and outer membrane protein structures. Species-specific differences of hydrophobic characteristics were not detected. Bacteria grown in fluid medium exhibited a high degree of hydrophobicity. Agar-grown bacteria showed hydrophobic interaction to a significant lower extent. By oxidation of LPS with sodium meta-periodate the hydrophobicity of agar-grown bacteria was slightly increased. Bacteria pretreated with proteinase K exhibited a marked decrease of hydrophobic interaction, whereas pretreatment with trypsin did not influence the hydrophobic interaction. Live bacteria were allowed to adhere to INT 407 cell membranes. With exception of one aflagellate strain, bacteria grown in fluid medium adhered better to the cellular substrate than agar-grown bacteria. This difference was not found when adhesion to fibronectin was tested. LPS-oxidized bacteria adhered significantly better to both cell membranes and fibronectin, whereas proteinase K treated bacteria exhibited a significant loss of adhesion capacity for both substrates.
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PMID:Hydrophobic characterization of thermophilic Campylobacter species and adhesion to INT 407 cell membranes and fibronectin. 907 18

Cell-fibronectin interactions, mediated through several different receptors, have been implicated in a wide variety of cellular properties. Among the cell surface receptors for fibronectin, integrins are the best characterized, particularly the prototype alpha5beta1 integrin. Using [125I]iodine cell surface labeling or metabolic radiolabeling with sodium [35S]sulfate, we identified alpha5beta1 integrin as the only sulfated integrin among beta1 integrin heterodimers expressed by the human melanoma cell line Mel-85. This facultative sulfation was confirmed not only by immunoprecipitation reactions using specific monoclonal antibodies but also by fibronectin affinity chromatography, two-dimensional electrophoresis, and chemical reduction. The covalent nature of alpha5beta1 integrin sulfation was evidenced by its resistance to treatments with high ionic, chaotrophic, and denaturing agents such as 4 M NaCl, 4 M MgCl2, 8 M urea, and 6 M guanidine HCl. Based on deglycosylation procedures as chemical beta-elimination, proteinase K digestion, and susceptibility to glycosaminoglycan lyases (chondroitinase ABC and heparitinases I and II), it was demonstrated that the alpha5beta1 heterodimer and alpha5 and beta1 integrin subunits were proteoglycans. The importance of alpha5beta1 sulfation was strengthened by the finding that this molecule is also sulfated in MG-63 (human osteosarcoma) and HCT-8 (human colon adenocarcinoma) cells.
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PMID:Post-translational modifications of alpha5beta1 integrin by glycosaminoglycan chains. The alpha5beta1 integrin is a facultative proteoglycan. 913 4


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