The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
P L Mäkinen - One of the best experts on this subject based on the ideXlab platform.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete treponema denticola atcc 35405
Infection and Immunity, 1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Certain periodontopathic organisms have been shown to exhibit high activity of Proline Iminopeptidase (PIPase). The human oral spirochete Treponema denticola ATCC 35405 was found to contain an easily extractable, novel PIPase (EC 3.4.11.5), which was purified to a sodium dodecyl sulfate- polyacrylamide gel electrophoresis-pure form by means of fast protein liquid chromatographic procedures. The range of the minimum monomeric molecular mass (280 amino acid residues) of the PIPase, based on amino acid analysis, was 30.35 to 30.39 kDa, but the likely in vivo form of the enzyme is a tetramer (minimum mass, 120.2 to 120.4 kDa). The molecular masses based on laser desorption mass spectrometry were 36.058 kDa for the monomer and 72.596 kDa for a dimer. The PIPase cleaves specifically the Pro-Y bond in dipeptides where Y is preferably Arg or Lys. Pro-Gln, Pro-Asn, and Pro-Ala were also good substrates, while Pro-Glu was hydrolyzed slowly and Pro-Asp was not hydrolyzed at all. Tripeptides were poor substrates or were not hydrolyzed (an exception was Pro-Gly-Gly, which cleaved at a moderate rate). Larger molecules, such as poly-L-Pro, were not hydrolyzed. The T. denticola enzyme can be regarded as a true PIPase, since replacing Pro in Pro-Y with other amino acid residues resulted in no hydrolysis. The activity of the PIPase may depend on an active carboxyl group and on an active seryl residue but not on metal cations. Diethylpyrocarbonate inactivated the enzyme in a reaction that was not reversible upon addition of NH2OH. The enzyme contains a relatively large percentage (ca. 15%) of Proline residues. The dominance of the PIPase activity among aminopeptidase activities present in T. denticola and the proposed location of the enzyme in the outer cell envelope suggest that it has a vital function in the propagation of the cells within their biological niche (inflamed human periodontal tissues). The biologic role of the PIPase may be envisaged as in the termination of the overall peptidolytic cascade (liberating free Proline and other amino acids), whereby host tissue proteins and peptides are first processed and inactivated by other peptidases possibly present within the same confines as the PIPase.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405. Infect. Immun
1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405
K K Mäkinen - One of the best experts on this subject based on the ideXlab platform.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete treponema denticola atcc 35405
Infection and Immunity, 1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Certain periodontopathic organisms have been shown to exhibit high activity of Proline Iminopeptidase (PIPase). The human oral spirochete Treponema denticola ATCC 35405 was found to contain an easily extractable, novel PIPase (EC 3.4.11.5), which was purified to a sodium dodecyl sulfate- polyacrylamide gel electrophoresis-pure form by means of fast protein liquid chromatographic procedures. The range of the minimum monomeric molecular mass (280 amino acid residues) of the PIPase, based on amino acid analysis, was 30.35 to 30.39 kDa, but the likely in vivo form of the enzyme is a tetramer (minimum mass, 120.2 to 120.4 kDa). The molecular masses based on laser desorption mass spectrometry were 36.058 kDa for the monomer and 72.596 kDa for a dimer. The PIPase cleaves specifically the Pro-Y bond in dipeptides where Y is preferably Arg or Lys. Pro-Gln, Pro-Asn, and Pro-Ala were also good substrates, while Pro-Glu was hydrolyzed slowly and Pro-Asp was not hydrolyzed at all. Tripeptides were poor substrates or were not hydrolyzed (an exception was Pro-Gly-Gly, which cleaved at a moderate rate). Larger molecules, such as poly-L-Pro, were not hydrolyzed. The T. denticola enzyme can be regarded as a true PIPase, since replacing Pro in Pro-Y with other amino acid residues resulted in no hydrolysis. The activity of the PIPase may depend on an active carboxyl group and on an active seryl residue but not on metal cations. Diethylpyrocarbonate inactivated the enzyme in a reaction that was not reversible upon addition of NH2OH. The enzyme contains a relatively large percentage (ca. 15%) of Proline residues. The dominance of the PIPase activity among aminopeptidase activities present in T. denticola and the proposed location of the enzyme in the outer cell envelope suggest that it has a vital function in the propagation of the cells within their biological niche (inflamed human periodontal tissues). The biologic role of the PIPase may be envisaged as in the termination of the overall peptidolytic cascade (liberating free Proline and other amino acids), whereby host tissue proteins and peptides are first processed and inactivated by other peptidases possibly present within the same confines as the PIPase.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405. Infect. Immun
1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405
C Y Chen - One of the best experts on this subject based on the ideXlab platform.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete treponema denticola atcc 35405
Infection and Immunity, 1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Certain periodontopathic organisms have been shown to exhibit high activity of Proline Iminopeptidase (PIPase). The human oral spirochete Treponema denticola ATCC 35405 was found to contain an easily extractable, novel PIPase (EC 3.4.11.5), which was purified to a sodium dodecyl sulfate- polyacrylamide gel electrophoresis-pure form by means of fast protein liquid chromatographic procedures. The range of the minimum monomeric molecular mass (280 amino acid residues) of the PIPase, based on amino acid analysis, was 30.35 to 30.39 kDa, but the likely in vivo form of the enzyme is a tetramer (minimum mass, 120.2 to 120.4 kDa). The molecular masses based on laser desorption mass spectrometry were 36.058 kDa for the monomer and 72.596 kDa for a dimer. The PIPase cleaves specifically the Pro-Y bond in dipeptides where Y is preferably Arg or Lys. Pro-Gln, Pro-Asn, and Pro-Ala were also good substrates, while Pro-Glu was hydrolyzed slowly and Pro-Asp was not hydrolyzed at all. Tripeptides were poor substrates or were not hydrolyzed (an exception was Pro-Gly-Gly, which cleaved at a moderate rate). Larger molecules, such as poly-L-Pro, were not hydrolyzed. The T. denticola enzyme can be regarded as a true PIPase, since replacing Pro in Pro-Y with other amino acid residues resulted in no hydrolysis. The activity of the PIPase may depend on an active carboxyl group and on an active seryl residue but not on metal cations. Diethylpyrocarbonate inactivated the enzyme in a reaction that was not reversible upon addition of NH2OH. The enzyme contains a relatively large percentage (ca. 15%) of Proline residues. The dominance of the PIPase activity among aminopeptidase activities present in T. denticola and the proposed location of the enzyme in the outer cell envelope suggest that it has a vital function in the propagation of the cells within their biological niche (inflamed human periodontal tissues). The biologic role of the PIPase may be envisaged as in the termination of the overall peptidolytic cascade (liberating free Proline and other amino acids), whereby host tissue proteins and peptides are first processed and inactivated by other peptidases possibly present within the same confines as the PIPase.
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Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405. Infect. Immun
1996Co-Authors: K K Mäkinen, C Y Chen, P L MäkinenAbstract:Proline Iminopeptidase from the outer cell envelope of the human oral spirochete Treponema denticola ATCC 35405
Francisco Javier Medrano - One of the best experts on this subject based on the ideXlab platform.
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structure of Proline Iminopeptidase from xanthomonas campestris pv citri a prototype for the prolyl oligopeptidase family
The EMBO Journal, 1998Co-Authors: Jorge Alonso, Jose Luis Garcia, Francisco Javier Medrano, Antonio A Romero, Wolfram Bode, F X GomisruthAbstract:The Proline Iminopeptidase from Xanthomonas campestris pv. citri is a serine peptidase that catalyses the removal of N‐terminal Proline residues from peptides with high specificity. We have solved its three‐dimensional structure by multiple isomorphous replacement and refined it to a crystallographic R ‐factor of 19.2% using X‐ray data to 2.7 A resolution. The protein is folded into two contiguous domains. The larger domain shows the general topology of the α/β hydrolase fold, with a central eight‐stranded β‐sheet flanked by two helices and the 11 N‐terminal residues on one side, and by four helices on the other side. The smaller domain is placed on top of the larger domain and essentially consists of six helices. The active site, located at the end of a deep pocket at the interface between both domains, includes a catalytic triad of Ser110, Asp266 and His294. Cys269, located at the bottom of the active site very close to the catalytic triad, presumably accounts for the inhibition by thiol‐specific reagents. The overall topology of this Iminopeptidase is very similar to that of yeast serine carboxypeptidase. The striking secondary structure similarity to human lymphocytic prolyl oligopeptidase and dipeptidyl peptidase IV makes this Proline Iminopeptidase structure a suitable model for the three‐dimensional structure of other peptidases of this family.
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crystallization and preliminary x ray diffraction analysis of Proline Iminopeptidase from xanthomonas campestris pv citri
FEBS Letters, 1997Co-Authors: Francisco Javier Medrano, Jorge Alonso, Jose Luis Garcia, Wolfram Bode, F X GomisruthAbstract:Abstract Proline Iminopeptidase from Xanthomonas campestris pv. citri , displaying no significant sequence homology to any protein previously analyzed by X-ray crystallography, has been crystallized using the vapour diffusion method. Two different orthorhombic crystal forms (space group C222 and I222) were obtained from a solution containing NaCl or polyethylene glycol monomethyl ether (MW 5000) as precipitating agent for the native and lanthanum-derivatized protein, respectively. Complete diffraction data sets have been collected up to 2.6 A (native) and 3.0 A (lanthanum derivative) resolution. Cell dimensions are a =147.2 A, b =167.8 A, and c =85.6 A (C222) and a =146.7 A, b =167.7 A, and c =171.4 A (I222), respectively. Considerations of the possible values of V m and analysis of the self-rotation function of the native crystals account for the presence of one dimer per asymmetric unit, whereas a tetramer probably would occupy the smallest crystallographically independent crystal portion in the lanthanum-derivatized protein crystals.
F X Gomisruth - One of the best experts on this subject based on the ideXlab platform.
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structure of Proline Iminopeptidase from xanthomonas campestris pv citri a prototype for the prolyl oligopeptidase family
The EMBO Journal, 1998Co-Authors: Jorge Alonso, Jose Luis Garcia, Francisco Javier Medrano, Antonio A Romero, Wolfram Bode, F X GomisruthAbstract:The Proline Iminopeptidase from Xanthomonas campestris pv. citri is a serine peptidase that catalyses the removal of N‐terminal Proline residues from peptides with high specificity. We have solved its three‐dimensional structure by multiple isomorphous replacement and refined it to a crystallographic R ‐factor of 19.2% using X‐ray data to 2.7 A resolution. The protein is folded into two contiguous domains. The larger domain shows the general topology of the α/β hydrolase fold, with a central eight‐stranded β‐sheet flanked by two helices and the 11 N‐terminal residues on one side, and by four helices on the other side. The smaller domain is placed on top of the larger domain and essentially consists of six helices. The active site, located at the end of a deep pocket at the interface between both domains, includes a catalytic triad of Ser110, Asp266 and His294. Cys269, located at the bottom of the active site very close to the catalytic triad, presumably accounts for the inhibition by thiol‐specific reagents. The overall topology of this Iminopeptidase is very similar to that of yeast serine carboxypeptidase. The striking secondary structure similarity to human lymphocytic prolyl oligopeptidase and dipeptidyl peptidase IV makes this Proline Iminopeptidase structure a suitable model for the three‐dimensional structure of other peptidases of this family.
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crystallization and preliminary x ray diffraction analysis of Proline Iminopeptidase from xanthomonas campestris pv citri
FEBS Letters, 1997Co-Authors: Francisco Javier Medrano, Jorge Alonso, Jose Luis Garcia, Wolfram Bode, F X GomisruthAbstract:Abstract Proline Iminopeptidase from Xanthomonas campestris pv. citri , displaying no significant sequence homology to any protein previously analyzed by X-ray crystallography, has been crystallized using the vapour diffusion method. Two different orthorhombic crystal forms (space group C222 and I222) were obtained from a solution containing NaCl or polyethylene glycol monomethyl ether (MW 5000) as precipitating agent for the native and lanthanum-derivatized protein, respectively. Complete diffraction data sets have been collected up to 2.6 A (native) and 3.0 A (lanthanum derivative) resolution. Cell dimensions are a =147.2 A, b =167.8 A, and c =85.6 A (C222) and a =146.7 A, b =167.7 A, and c =171.4 A (I222), respectively. Considerations of the possible values of V m and analysis of the self-rotation function of the native crystals account for the presence of one dimer per asymmetric unit, whereas a tetramer probably would occupy the smallest crystallographically independent crystal portion in the lanthanum-derivatized protein crystals.
