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PubMed2002

Expression of a synthetic gene encoding the Asp-hemolysin from Aspergillus fumigatus in Escherichia coli.

Asp-hemolysin is a hemolytic toxin from Aspergillus fumigatus and is a specific binding protein with high affinity for oxidized low density lipoprotein (Ox-LDL). As a first step in clarifying the structure-function relationship of Asp-hemolysin, we expressed Asp-hemolysin in Escherichia coli (E. coli) as a fusion protein with a maltose-binding protein (MBP) and purified it by affinity chromatography on an amylose resin. The apparent molecular size of the protein produced by E. coli was approximately 57 kDa, as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. This is consistent with the predicted molecular size of 56.9 kDa for a fusion protein which includes 14.2 kDa of Asp-hemolysin and 42.7 kDa from MBP. The purified recombinant Asp-hemolysin showed an immunoreactivity with the anti-Asp-hemolysin antibody as revealed by western blot analysis. Furthermore, in dot blot analysis, MBP-Asp-hemolysin fusion protein exhibited binding activity to Ox-LDL as did native Asp-hemolysin.

ATP-Binding Cassette Transporters↗

PubMed2002

A novel oxidized low-density lipoprotein-binding protein, Asp-hemolysin, recognizes lysophosphatidylcholine.

Oxidized low-density lipoprotein (Ox-LDL) plays an important role in the initiation and progression of atherosclerosis. Asp-hemolysin, a hemolytic toxin from Aspergillus fumigatus, is a specific, high affinity binding protein for Ox-LDL. We have previously shown that Ox-LDL strongly inhibits the hemolytic activity of Asp-hemolysin, and that the removal of lysophosphatidylcholine (lysoPC) from Ox-LDL abolished the inhibition. In the present study, to clarify the binding mechanism of Asp-hemolysin to Ox-LDL, we investigated the interaction between Asp-hemolysin and lysoPC as a typical lipid moiety of Ox-LDL. Based on western blot analysis, the binding of Asp-hemolysin to LDL, oxidized for different times, depended on the lysoPC content in each Ox-LDL. In addition, the inhibition of lysoPC production in Ox-LDL by phenylmethylsulfonyl fluoride (PMSF) pretreatment of LDL resulted in a marked decrease of Asp-hemolysin binding to PMSF-pretreated Ox-LDL. Furthermore, the binding analysis of Asp-hemolysin to lysoPC using ion-exchange chromatography revealed that Asp-hemolysin directly binds to lysoPC.

Blotting, Western↗

PubMed2005

Imaging alpha-hemolysin with molecular dynamics: ionic conductance, osmotic permeability, and the electrostatic potential map.

alpha-Hemolysin of Staphylococcus aureus is a self-assembling toxin that forms a water-filled transmembrane channel upon oligomerization in a lipid membrane. Apart from being one of the best-studied toxins of bacterial origin, alpha-hemolysin is the principal component in several biotechnological applications, including systems for controlled delivery of small solutes across lipid membranes, stochastic sensors for small solutes, and an alternative to conventional technology for DNA sequencing. Through large-scale molecular dynamics simulations, we studied the permeability of the alpha-hemolysin/lipid bilayer complex for water and ions. The studied system, composed of approximately 300,000 atoms, included one copy of the protein, a patch of a DPPC lipid bilayer, and a 1 M water solution of KCl. Monitoring the fluctuations of the pore structure revealed an asymmetric, on average, cross section of the alpha-hemolysin stem. Applying external electrostatic fields produced a transmembrane ionic current; repeating simulations at several voltage biases yielded a current/voltage curve of alpha-hemolysin and a set of electrostatic potential maps. The selectivity of alpha-hemolysin to Cl(-) was found to depend on the direction and the magnitude of the applied voltage bias. The results of our simulations are in excellent quantitative agreement with available experimental data. Analyzing trajectories of all water molecule, we computed the alpha-hemolysin's osmotic permeability for water as well as its electroosmotic effect, and characterized the permeability of its seven side channels. The side channels were found to connect seven His-144 residues surrounding the stem of the protein to the bulk solution; the protonation of these residues was observed to affect the ion conductance, suggesting the seven His-144 to comprise the pH sensor that gates conductance of the alpha-hemolysin channel.

Bacterial Toxins↗

PubMed2004

A role for histone-like protein H1 (H-NS) in the regulation of hemolysin expression by Serratia marcescens.

The histone-like protein H1 (H-NS) is an abundant structural component of the bacterial nucleoid and influences many cellular processes including recombination, transcription and transposition. Mutations in the hns gene encoding H-NS are highly pleiotropic, affecting the expression of many unrelated genes. We have studied the role of H-NS on the regulation of hemolysin gene expression in Serratia marcescens. The Escherichia coli hns mutant carrying S. marcescens hemolysin genes on a plasmid constructed by ligation of the 3.2-kb HindIII-SacI fragment of pR02 into pBluescriptIIKS, showed a high level of expression of this hemolytic factor. To determine the osmoregulation of wild-type and hns defective mutants the cells were grown to mid-logarithmic phase in LB medium with 0.06 or 0.3 M NaCl containing ampicillin and kanamycin, whereas to analyze the effect of pH on hemolysin expression, the cells were grown to late-logarithmic phase in LB medium buffered with 0.1 M Tris-HCl, pH 4.5 to 8.0. To assay growth phase-related hemolysin production, bacterial cells were grown in LB medium supplemented with ampicillin and kanamycin. The expression of S. marcescens hemolysin genes in wild-type E. coli and in an hns-defective derivative at different pH and during different growth phases indicated that, in the absence of H-NS, the expression of hemolysin did not vary with pH changes or growth phases. Furthermore, the data suggest that H-NS may play an important role in the regulation of hemolysin expression in S. marcescens and its effect may be due to changes in DNA topology influencing transcription and thus the amount of hemolysin expression. Implications for the mechanism by which H-NS influences gene expression are discussed.

Bacterial Proteins↗

PubMed1991

Subhemolytic doses of Escherichia coli hemolysin evoke large quantities of lipoxygenase products in human neutrophils.

Polymorphonuclear leukocytes (PMN) have been identified as preferred target cells for Escherichia coli hemolysin in human blood (Bhakdi, S., Greulich, S., Muhly, M., Eberspächer, B., Becker, H., Thiele, A., and Hugo, F. (1989) J. Exp. Med. 169, 737-754). Leukotriene and 5-hydroxyeicosatetraenoic acid generation was investigated in human PMN challenged with E. coli hemolysin in the absence or presence of free arachidonic acid or eicosapentaenoic acid (EPA). In the absence of exogenous free fatty acids, E. coli hemolysin (0.01-10 hemolytic units/ml) induced moderate generation of leukotriene B4 (LTB4) and its omega-oxidation products. The presence of free arachidonic acid (10 microM) during E. coli hemolysin (0.1 hemolytic unit/ml) challenge evoked the generation of large quantities of these products (greater than 100 pmol/1.5 x 10(7) PMN). In parallel, large amounts of 5-hydroxyeicosatetraenoic acid and nonenzymatic LTA4 hydrolysis products appeared. Product release peaked or plateaued 5-10 min after E. coli hemolysin challenge. The presence of exogenous EPA upon E. coli hemolysin challenge resulted in the exclusive generation of LTB5 and metabolites, LTA5 decay products and 5-hydroxyeicosapentaenoic acid. Dose and time dependences corresponded to those with arachidonic acid provision, and the total of EPA-derived products surpassed that of arachidonic acid metabolites in corresponding experiments approximately 2-fold. Increasing the time between free fatty acid provision and E. coli hemolysin challenge resulted in a rapid decline in the generation of arachidonic acid or EPA metabolites. Thus, subhemolytic doses of E. coli hemolysin evoke marked PMN eicosanoid generation that is dependent on exogenous free fatty acid supply, with total amounts approximating those found in calcium ionophore-stimulated neutrophils.

Bacterial Proteins↗

PubMed1970

Effects of Listeria monocytogenes Hemolysin on Phagocytic Cells and Lysosomes.

The effects of Listeria monocytogenes hemolysin on lysosomes and phagocytic cells were investigated. Hemolysin caused release of beta-glucuronidase and acid phosphatase from suspensions of rabbit and rat lysosomes prepared from liver homogenates. The degree of lysis was proportional to the concentration of hemolysin added. There appeared to be no significant difference between the sensitivities of rat and rabbit lysosomes to disruption. Studies on the effect of pH and temperature on lytic activity suggested that hemolysin could function under conditions which might exist within phagocytic cells. Peritoneal exudates from rabbits and mice were exposed to hemolysin and observed by phase microscopy. Hemolysin possessed leucocidal activity and caused degranulation of both rabbit and mouse cells. Optimal activity against lysosomes and peritoneal exudate cells required activation of hemolysin with a reducing agent and could be prevented if hemolysin was previously incubated with cholesterol.

Journal Article↗

PubMed1965

PURIFICATION OF STAPHYLOCOCCAL BETA-HEMOLYSIN AND ITS ACTION ON STAPHYLOCOCCAL AND STREPTOCOCCAL CELL WALLS.

Chesbro, William R. (University of New Hampshire, Durham), Fred P. Heydrick, Roland Martineau, and Gail N. Perkins. Purification of staphylococcal beta-hemolysin and its action on staphylococcal and streptococcal cell walls. J. Bacteriol. 89:378-389. 1965.-After growth of bovine-derived strains of Staphylococcus aureus in a completely dialyzable medium, the beta-hemolysin in the culture supernatant fluids was purified by gradient-elution chromatography on cellulose phosphate. The purified hemolysin contained two components, demonstrable by immunodiffusion or electrophoresis, but was free from alpha-hemolysin, coagulase, Delta-hemolysin, enterotoxins A and B, glucuronidase, hyaluronidase, lipase, muramidase, Panton-Valentine leukocidin, phosphatase, and protease. The hemolysin was heat-labile and sulfhydryl-dependent, and the preparation was leukocidal for guinea pig macrophages. When rabbit red blood cell (RBC) stroma and staphylococcal or enterococcal cell walls were treated with the purified hemolysin, it liberated mucopolysaccharides from the rabbit RBC stroma, polysaccharides and mucopolysaccharides (or mucopeptides) from the staphyloccoal cell walls, and rhamnose, glucose, an unidentified monosaccharide, N-acetylglucosamine, and at least two polysaccharides from the enterococcal cell walls. The hemolytic and cell-wall degradative activities had similar thermal inactivation kinetics, pH optima, sedimentation coefficients, and chromatographic and electrophoretic mobilities; both required Mg and were inhibited by thiol-inactivating agents. Consequently, it seems likely that both activities are expressions of the same enzyme.

Animals↗

PubMed1990

[Distribution and transcription of determinants homologous to the alpha-hemolysin (hlY) gene in the genomes of HLY- and HLY+ staphylococci].

The molecular organization of the alpha-hemolysin gene from Staphylococcus aureus strain O15 has been studied. Hybridization of the DNA from this strain with the [32P]-labeled cloned fragment containing alpha-hemolysin gene has shown the studied gene to be unique in the genome of the strain. Sequences homologous to the gene were not found to be dispersed along the genome of Staphylococcus aureus O15. The presence of alpha-hemolysin gene in some Staphylococcus epidermidis strains has been monitored. The strains 1413, 303 have been demonstrated to contain no gene for alpha-hemolysin. The hemolysin genes were found in the genomes of the strains 159, 169, 180 by DNA hybridization technique. In the genome of the strain 180 the long region including the right end of alpha-hemolysin gene is deleted. Hybridization with the net RNA of these strains shows the absence of transcription of intact as well as deleted alpha-hemolysin genes.

Cloning, Molecular↗

PubMed1996

Molecular cloning, characterization, and sequencing of the hemolysin gene from Edwardsiella tarda.

Hemolysis is a major symptom of diseased eels infected by Edwardsiella tarda. The hemolysin gene of E. tarda strain ET16 was cloned into plasmid pSK and expressed in Escherichia coli. The mol. mass of the functional beta-hemolysin was estimated to be approximately 34 kDa by gel filtration and by SDS-PAGE followed by in situ hemolysin activity analysis. The cloned fragment containing the beta-hemolysin locus from E. tarda strain ET16 expressed in E. coli was estimated to be 5.3 kb in length; the deduced gene product was identical in mol. mass and properties to the extracellular products of E. tarda strain ET16. The presence of EcoRI and XbaI sites within the beta-hemolysin gene of E. tarda was determined from the loss of hemolytic activity in subclones. Analysis of the DNA sequence of a 2,436-bp HaeIII-HindIII fragment that included EcoRI and XbaI sites revealed three ORFs organized as an operon that encoded three predicted polypeptides of 15,874, 7,055, and 34,804 Da. A 34-kDa polypeptide expressing hemolytic activity in cell lysates of the clone DH5 alpha(pETH3E) is very likely the beta-hemolysin encoded by the third ORF. The observation that hemolytic activity appeared in the culture medium of E. tarda, but not in that of E. coli strain DH5 alpha(pETH3E) indicates the existence of a mechanism for transporting the hemolysin across the cell envelope in E. tarda that is different from that of E. coli.

Amino Acid Sequence↗

PubMed1991

Identity of hemolysins produced by Bacillus thuringiensis and Bacillus cereus.

A hemolysin (Bt-hemolysin) produced by Bacillus thuringiensis var. kurstaki HD-1 producing crystalline toxin(s) was purified by successive treatments of ammonium sulfate (45-65%) and column chromatography using DEAE-cellulose, Sephadex G-75 and KB-002 (a hydroxyapatite column for fast protein liquid chromatography). A hemolysin (Bc-hemolysin) produced by B. cereus HG-6A was also purified by the same procedure. The purified Bt-hemolysin and Bc-hemolysin, both of which are thiol-activated hemolysins, were biologically, physicochemically and immunologically identical. These findings provide further evidence of the similarity of B. thuringiensis, which is being used as a biological insecticide, to B. cereus, a toxigenic organism of food poisoning.

Bacillus cereus↗

PubMed1985

Orientation and expression of the cloned hemolysin gene of Pseudomonas aeruginosa.

The structural gene for Pseudomonas aeruginosa hemolysin, carried on recombinant plasmid pSL2 and cloned in Escherichia coli, was analyzed by insertional and deletional mutagenesis. Expression of the hemolysin was blocked by insertion of transposon Tn5 into different locations. Two of the mutants allowed detectable synthesis of truncated hemolysin polypeptides of two different sizes and thus defined the structural gene. The location of the hemolysin gene in the recombinant plasmid, and the direction of transcription, were further established by nuclease BAL 31 digestion, and by construction of gene fusions between hemolysin and beta-galactosidase. Evidently, the tet promoter contributed to the majority of the expression of cloned hemolysin gene, but the Pseudomonas promoter was present in the cloned DNA and was functional in E. coli since inactivation of the tet promoter either by Tn5 insertion or by deletion decreased synthesis of the 80-kDal hemolysin but did not fully abolish it.

Chromosome Mapping↗

PubMed1991

Immunological characterization of breakdown peptides of the 104 kilodalton hemolysin of Actinobacillus pleuropneumoniae serotype 1.

The 104 kilodalton (kDa) hemolysin of Actinobacillus pleuropneumoniae serotype 1, strain CM-5 was precipitated from RPMI-1640 culture supernatant using ammonium sulfate to 80% saturation. In immunoblots, a rabbit polyclonal antiserum against the 104 kDa hemolysin protein, recognized not only the original 104 kDa monomeric form of the hemolysin but other proteins in the crude antigen mixture ranging in molecular mass from 43 to greater than 125 kDa. The antiserum was able to crosslink these proteins to active hemolysin in RPMI-1640 culture supernatant resulting in bands of hemolysis in blood agar used in a contact assay. Corresponding to these bands of hemolysis, denatured peptides with molecular masses of 51, 85, 104 and greater than 125 kDa were excised and injected into rabbits. In immunoblots, the resultant antibodies recognized the injected peptide and the monomeric 104 kDa protein. However, only the rabbit antisera produced against the 104 and 125 kDa proteins contained antibodies which neutralized the active 104 kDa hemolysin in culture supernatant. These results indicate that (i) the 104 kDa protein hemolysin can exist in a higher molecular weight aggregate (greater than 125 kDa) but can also break down to peptides which have molecular masses smaller than the 104 kDa parent molecule and (ii) while several epitopes are present in the hemolysin molecule, there seems to be a restricted number of antigenic determinants responsible for inducing neutralizing antibodies and these seem to reside only in the 104 kDa parent molecule. This may have consequences, in terms of vaccine development, for the control of pleuropneumonia in swine herds.

Actinobacillus pleuropneumoniae↗

PubMed2004

Use of the alpha-hemolysin secretion system of Escherichia coli for antigen delivery in the Salmonella typhi Ty21a vaccine strain.

This study examined the suitability of the hemolysin secretion system of Escherichia coli for expression and delivery of alpha-hemolysin (HlyA) by the S. typhi Ty21a strain, the only live oral Salmonella vaccine strain licensed for human use, under in vitro and in vivo conditions. For this purpose, two plasmid vectors encoding either the whole alpha-hemolysin of E. coli (pANN202-812/pMOhly2) or the hemolysin secretion signal (pMOhly1) were transferred into S. typhi Ty21a. S. typhi Ty21a carrying pANN202-812/pMOhly2 revealed efficient secretion of hemolysin in vitro. After formulation according to a process suitable for commercial production of Salmonella-based live bacterial vaccines, plasmids were shown to be stable in Ty21a and hemolysin secretion was demonstrated even after storage of the strains under real-time and stress conditions. After intranasal immunization of mice with S. typhi Ty21a/pANN202-812 plasmids are stable in vivo, and immunization induced a profound immune response against the heterologous HlyA antigen. Therefore, the combination of the hemolysin secretion system and S. typhi Ty21a could form the basis for a new generation of live bacterial vaccines.

Animals↗

PubMed1990

In vitro cytotoxic effect of alpha-hemolytic Escherichia coli on human blood granulocytes. Inhibition by alpha-hemolysin antibody.

The influence of alpha-hemolysin antibody on the in vitro cytotoxic effect of alpha-hemolytic Escherichia coli bacteria and culture filtrates was investigated. Damage to human blood granulocytes was quantified by measuring the release of chromium 51 from labelled cells in the presence of whole or fractionated plasma containing alpha-hemolysin antibody. Anti-alpha-hemolysin activity was found exclusively in the IgG fraction of plasma. Human plasma contained "natural" alpha-hemolysin antibody to various titers. Vaccination of rabbits resulted in only modest rises in alpha-hemolysin antibody titers. The cytotoxic effect of alpha-hemolytic E. coli bacteria as well as that of bacterial culture filtrates was reduced in a titer-dependent way in the presence of plasma containing alpha-hemolysin antibody. These results indicate that the cytotoxic effect of alpha-hemolytic E. coli is inhibited by alpha-hemolysin antibody.

Adult↗

PubMed2003

Leukotriene-mediated coronary vasoconstriction and loss of myocardial contractility evoked by low doses of Escherichia coli hemolysin in perfused rat hearts.

OBJECTIVE: hemolysin has been implicated as an important pathogenic factor in extraintestinal infections including sepsis. We investigated the effects of coronary administration of hemolysin on cardiac function in isolated rat hearts perfused at constant flow. DESIGN: Prospective, experimental study. SETTING: Research laboratory at a university hospital. SUBJECTS: Isolated hearts from male Wistar rats. INTERVENTIONS: Isolated hearts were perfused with purified hemolysin for 60 min. MEASUREMENTS AND MAIN RESULTS: Low concentrations of the toxin in the perfusate (0.1-0.2 hemolytic units/mL) caused a dose-dependent coronary vasoconstriction with a marked increase in coronary perfusion pressure, which was paralleled by a decrease in left ventricular developed pressure (and the maximum rate of left ventricular pressure increase). Moreover, 0.2 hemolytic units/mL hemolysin evoked ventricular fibrillation within 10 mins of toxin application. These events were accompanied by the liberation of leukotrienes (LTC4, LTD4, LTE4, and LTB4), thromboxane A2, prostaglandin I2, and the cell necrosis markers lactate dehydrogenase and creatine kinase into the recirculating perfusate. The lipoxygenase inhibitor MK-886 fully blocked the toxin-induced coronary vasoconstrictor response and the loss of myocardial contractility and reduced the release of lactate dehydrogenase and creatine kinase. In contrast to this, the cyclooxygenase inhibitor indomethacin was entirely ineffective. In addition, hemolysin elicited an increase in heart weight and left ventricular end-diastolic pressure, the latter again being suppressed by MK-886. CONCLUSIONS: Low doses of hemolysin cause strong coronary vasoconstriction, linked with loss of myocardial performance, release of cell injury enzymes, and electrical instability, with all events being largely attributable to toxin-elicited leukotriene generation in the coronary vasculature. Bacterial exotoxins such as hemolysin thus may be implicated in the cardiac abnormalities encountered in septic shock.

Animals↗

PubMed1984

Characterization of inhibitor to leptospiral hemolysin present in bovine serum.

Hemolysis by leptospiral hemolysin was strongly inhibited by bovine serum. The inhibitory activity was observed in the chloroform-methanol-soluble fraction of bovine serum. The inhibitor was eluted in a complex lipid fraction and was separated into two fractions (Fr. I and II) by silicic acid column chromatography. Fractions I and II inhibited approximately 75% and 95%, respectively, of hemolysis by leptospiral hemolysin. Fraction I was identified as phosphatidylethanolamine (PdE) by silica gel thin-layer chromatography (TLC). Two kinds of phospholipids (PLs) were detected in Fr. II by TLC. One was resistant to alkaline treatment and was identified as sphingomyelin (Spm), and the other was sensitive to such treatment and was identified as phosphatidylcholine (PdC). PLs, such as Spm, PdC, phosphatidylglycerol, PdE, phosphatidylserine and cardiolipin, inhibited hemolysis by leptospiral hemolysin, but phosphatidylinositol did not show any inhibitory activity. PLs lacking the amino group in the polar backbone of the molecules were more effective. From experiments using erythrocytes of various kinds of animals, it was revealed that the hemolytic sensitivity of mammalian erythrocytes to leptospiral hemolysin depended on the Spm content in the erythrocyte membrane. On the other hand, phospholipase C (PLase C) activity with Spm and PdC as substrates was detected in the culture supernatant of Leptospira. Therefore, leptospiral hemolysin was presumed to be PLase C, perhaps sphingomyelinase. The inhibitors of leptospiral hemolysin present in bovine serum were identified as PLs. PLs in bovine serum were suggested to function as inhibitors of the interaction between leptospiral hemolysin and the surface of the erythrocyte membrane.

Animals↗

PubMed1997

Interactions between Fusobacterium necrophorum hemolysin, erythrocytes and erythrocyte membranes.

The interactions between the hemolysin of Fusobacterium necrophorum subsp. necrophorum, erythrocytes and erythrocyte membranes were studied as an attempt to determine the initial characteristics leading to hemolysis. The spectrum of erythrocyte sensitivity indicated that horse, dog and mouse erythrocytes were highly sensitive whereas those of cattle, sheep, goat and chicken were insensitive to the hemolysin. Binding of hemolysin to horse and dog erythrocytes or their ghosts was more pronounced than to those of cattle and sheep as detected by a decrease of hemolytic activity from hemolysin preparations. The kinetics of hemolysis revealed that lysis is preceded by a prelytic phase characterized by binding of hemolysin to erythrocytes. Treatment of horse erythrocytes with hemolysin at various temperatures prior to incubation at 37 degrees C also revealed that this binding prelytic phase is temperature independent. This was followed by a temperature dependent lytic stage since erythrocytes pretreated with hemolysin and incubated at 4 degrees C showed no hemolysis. An inverse relation was found between erythrocyte concentration and hemolytic activity suggesting a multiple-hit mechanism of hemolysis.

Animals↗

PubMed1999

Purification and characterization of hemolysin from Porphyromonas gingivalis A7436.

Porphyromonas gingivalis, a periodontal pathogen, has the ability to lyse erythrocytes. The hemolytic activity of P. gingivalis A7436 was purified as a 45-kDa protein from the culture supernatant of a 3-days old culture using nickel-nitrilotriacetic acid chromatography. Erythrocytes treated with purified P. gingivalis hemolysin showed the presence of pores and extracellular debris by scanning electron microscopy. Active immunization of mice with 15 micrograms hemolysin induced neutralizing antibodies to hemolysin. Heating at 60 degrees C and treatment with trypsin and dithiothreitol abolished hemolytic activity, while incubation with the protease inhibitor Na-p-tosyl-L-lysine chloromethyl ketone caused no effect. We report here for the first time purification of a hemolysin from P. gingivalis A7436. The amino acid sequence of an internal peptide of hemolysin showed sequence similarity with fimbrillin from P. gingivalis HG564. However, the amino acid composition of purified hemolysin was different from that of P. gingivalis fimbrillin. Also, the ability to lyse but not agglutinate erythrocytes and to bind to nickel-nitrilotriacetic acid differentiates P. gingivalis hemolysin from fimbrillin.

Amino Acid Sequence↗