The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
H Kagan - One of the best experts on this subject based on the ideXlab platform.
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modulation of lysyl oxidase activity toward peptidyl lysine by vicinal dicarboxylic amino acid residues implications for collagen cross linking
Journal of Biological Chemistry, 1994Co-Authors: Narasimhan Nagan, H KaganAbstract:The substrate specificity of lysyl oxidase has been explored with synthetic oligopeptides. kcat/Km increased with increasing peptide length in Ac-(Gly)n-Lys-(Gly)n-CONH2 (n = 1-5). Using 11-mers as the standard peptide length, Glu immediately N-terminal to Lys increased kcat/Km 8.8-fold over that for the -Lys-Glu- sequence and 4.9-fold over the glutamate-free control. Kinetic constants were significantly less perturbed when Glu was 2 or more residues distant from Lys. Replacement of Glu in -Glu-Lys- with Gln significantly increased Km and lowered kcat/Km. Asp rather than Glu N-terminal to Lys decreased Km similar to that of the -Glu-Lys- 11-mer, although the kcat decreased considerably, indicating that lysyl oxidase responds to the side chain length of vicinal Asp or Glu at this position. -Asp-Glu-Lys- within an 11-mer was not oxidized, although this sequence is oxidized within the N-terminal telopeptide of the alpha 1(I) chain in type I collagen fibrils. Thus, lysyl oxidase exhibits distinct preferences for sequences vicinal to lysine. These results are discussed with respect to a model requiring collagen fibril formation prior to oxidation of lysine in collagen by lysyl oxidase.
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modulation of lysyl oxidase activity toward peptidyl lysine by vicinal dicarboxylic amino acid residues
1994Co-Authors: Narasimhan Nagan, H KaganAbstract:The substrate specificity of purified lysyl oxidase has been explored with synthetic, 11-mer oligopeptides. -Glu-Lys-in Ac-Glyn(Glu,Lys)Glym-NH2 was a more favorable substrate than the glutamate-free control peptide and considerably more favorable than the -Lys-Glu- sequence as well as sequences in which Glu was separated from Lys by intervening Gly residues. The kcat for the -Asp-Glu- sequence was markedly reduced from that of the -Glu-Lys- sequence, indicating that lysyl oxidase responds to the side chain length of vicinal Asp or Glu at this position. -Asp-Glu-Lys-within an 11-mer was not oxidized, although this sequence is oxidized within the N-telopeptide of the α 1(I) chain in type I collagen fibrils. Thus, lysyl oxidase exhibits distinct preferences for sequences vicinal to lysine. These results are discussed with respect to a model requiring collagen fibril formation prior to oxidation of lysine in collagen by lysyl oxidase.
Stanley J Korsmeyer - One of the best experts on this subject based on the ideXlab platform.
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bax induced cell death may not require interleukin 1β converting enzyme like proteases
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jialing Xiang, Debra T Chao, Stanley J KorsmeyerAbstract:Expression of BAX, without another death stimulus, proved sufficient to induce a common pathway of apoptosis. This included the activation of interleukin 1β-converting enzyme (ICE)-like proteases with cleavage of the endogenous substrates poly(ADP ribose) polymerase and D4-GDI (GDP dissociation inhibitor for the rho family), as well as the fluorogenic peptide acetyl-Asp-Glu-Val-Asp-aminotrifluoromethylcoumarin (DEVD-AFC). The inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk) successfully blocked this protease activity and prevented FAS-induced death but not BAX-induced death. Blocking ICE-like protease activity prevented the cleavage of nuclear and cytosolic substrates and the DNA degradation that followed BAX induction. However, the fall in mitochondrial membrane potential, production of reactive oxygen species, cytoplasmic vacuolation, and plasma membrane permeability that are downstream of BAX still occurred. Thus, BAX-induced alterations in mitochondrial function and subsequent cell death do not apparently require the known ICE-like proteases.
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bax induced cell death may not require interleukin 1β converting enzyme like proteases
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jialing Xiang, Debra T Chao, Stanley J KorsmeyerAbstract:Expression of BAX, without another death stimulus, proved sufficient to induce a common pathway of apoptosis. This included the activation of interleukin 1 beta-converting enzyme (ICE)-like proteases with cleavage of the endogenous substrates poly(ADP ribose) polymerase and D4-GDI (GDP dissociation inhibitor for the rho family), as well as the fluorogenic peptide acetyl-Asp-Glu-Val-Asp-aminotrifluoromethylcoumarin (DEVD-AFC). The inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk) successfully blocked this protease activity and prevented FAS-induced death but not BAX-induced death. Blocking ICE-like protease activity prevented the cleavage of nuclear and cytosolic substrates and the DNA degradation that followed BAX induction. However, the fall in mitochondrial membrane potential, production of reactive oxygen species, cytoplasmic vacuolation, and plasma membrane permeability that are downstream of BAX still occurred. Thus, BAX-induced alterations in mitochondrial function and subsequent cell death do not apparently require the known ICE-like proteases.
Hiroshi Homma - One of the best experts on this subject based on the ideXlab platform.
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localization transport and uptake of d aspartate in the rat adrenal and pituitary glands
Archives of Biochemistry and Biophysics, 2001Co-Authors: Jen Ai Lee, Zhiqun Long, Noriyuki Nimura, Takeshi Iwatsubo, Kazuhiro Imai, Hiroshi HommaAbstract:Large amounts of D-aspartate (D-Asp) are present in the rat adrenal and pituitary glands. D-Asp is thought to be synthesized in the mammalian body and also accumulates in various tissues following intraperitoneal or intravenous administration. This report examines the origins of D-Asp in the adrenal and pituitary glands. We administered D-Asp to male rats intraperitoneally and immunolocalized this exogenous D-Asp in adrenal and pituitary tissue, using an anti-D-Asp antiserum which was previously developed in our laboratory. D-Asp levels in the rat adrenal gland have been shown to undergo a transient increase at 3 weeks of age and to decrease rapidly thereafter. We found that in the adrenal gland, exogenous D-Asp administered intraperitoneally was incorporated into the same region of the adrenal cortex in which endogenous D-Asp was present. By Northern and Western blot analysis and immunohistochemistry of glutamate (Glu) transporter, we also found that expression of the Glu transporter (GLAST), which has an affinity for D-Asp, transiently increased at 3 weeks of age and that localization patterns of the Glu transporter within the tissue were almost coincident with those of endogenous D-Asp. These observations suggest that D-Asp in the adrenal cortex of 3-week-old male rats is primarily acquired by uptake from the vascular system. We have previously shown that D-Asp is specifically localized in prolactin (PRL)-containing cells in the anterior lobe of the adult rat pituitary gland. Here we report that in the pituitary gland, exogenous D-Asp accumulated in endothelial cells, but not in PRL-containing cells. Northern and Western blot analysis and immunohistochemistry of Glu transporter revealed that developmental changes in the Glu transporter (GLAST) expression did not correlate with tissue levels of D-Asp and that the Glu transporter was not expressed in PRL-containing cells. These observations suggest that, in contrast to the adrenal gland, most of the D-Asp in the pituitary gland of adult male rats originates inside the gland itself.
Narasimhan Nagan - One of the best experts on this subject based on the ideXlab platform.
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modulation of lysyl oxidase activity toward peptidyl lysine by vicinal dicarboxylic amino acid residues implications for collagen cross linking
Journal of Biological Chemistry, 1994Co-Authors: Narasimhan Nagan, H KaganAbstract:The substrate specificity of lysyl oxidase has been explored with synthetic oligopeptides. kcat/Km increased with increasing peptide length in Ac-(Gly)n-Lys-(Gly)n-CONH2 (n = 1-5). Using 11-mers as the standard peptide length, Glu immediately N-terminal to Lys increased kcat/Km 8.8-fold over that for the -Lys-Glu- sequence and 4.9-fold over the glutamate-free control. Kinetic constants were significantly less perturbed when Glu was 2 or more residues distant from Lys. Replacement of Glu in -Glu-Lys- with Gln significantly increased Km and lowered kcat/Km. Asp rather than Glu N-terminal to Lys decreased Km similar to that of the -Glu-Lys- 11-mer, although the kcat decreased considerably, indicating that lysyl oxidase responds to the side chain length of vicinal Asp or Glu at this position. -Asp-Glu-Lys- within an 11-mer was not oxidized, although this sequence is oxidized within the N-terminal telopeptide of the alpha 1(I) chain in type I collagen fibrils. Thus, lysyl oxidase exhibits distinct preferences for sequences vicinal to lysine. These results are discussed with respect to a model requiring collagen fibril formation prior to oxidation of lysine in collagen by lysyl oxidase.
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modulation of lysyl oxidase activity toward peptidyl lysine by vicinal dicarboxylic amino acid residues
1994Co-Authors: Narasimhan Nagan, H KaganAbstract:The substrate specificity of purified lysyl oxidase has been explored with synthetic, 11-mer oligopeptides. -Glu-Lys-in Ac-Glyn(Glu,Lys)Glym-NH2 was a more favorable substrate than the glutamate-free control peptide and considerably more favorable than the -Lys-Glu- sequence as well as sequences in which Glu was separated from Lys by intervening Gly residues. The kcat for the -Asp-Glu- sequence was markedly reduced from that of the -Glu-Lys- sequence, indicating that lysyl oxidase responds to the side chain length of vicinal Asp or Glu at this position. -Asp-Glu-Lys-within an 11-mer was not oxidized, although this sequence is oxidized within the N-telopeptide of the α 1(I) chain in type I collagen fibrils. Thus, lysyl oxidase exhibits distinct preferences for sequences vicinal to lysine. These results are discussed with respect to a model requiring collagen fibril formation prior to oxidation of lysine in collagen by lysyl oxidase.
Jialing Xiang - One of the best experts on this subject based on the ideXlab platform.
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bax induced cell death may not require interleukin 1β converting enzyme like proteases
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jialing Xiang, Debra T Chao, Stanley J KorsmeyerAbstract:Expression of BAX, without another death stimulus, proved sufficient to induce a common pathway of apoptosis. This included the activation of interleukin 1β-converting enzyme (ICE)-like proteases with cleavage of the endogenous substrates poly(ADP ribose) polymerase and D4-GDI (GDP dissociation inhibitor for the rho family), as well as the fluorogenic peptide acetyl-Asp-Glu-Val-Asp-aminotrifluoromethylcoumarin (DEVD-AFC). The inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk) successfully blocked this protease activity and prevented FAS-induced death but not BAX-induced death. Blocking ICE-like protease activity prevented the cleavage of nuclear and cytosolic substrates and the DNA degradation that followed BAX induction. However, the fall in mitochondrial membrane potential, production of reactive oxygen species, cytoplasmic vacuolation, and plasma membrane permeability that are downstream of BAX still occurred. Thus, BAX-induced alterations in mitochondrial function and subsequent cell death do not apparently require the known ICE-like proteases.
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bax induced cell death may not require interleukin 1β converting enzyme like proteases
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jialing Xiang, Debra T Chao, Stanley J KorsmeyerAbstract:Expression of BAX, without another death stimulus, proved sufficient to induce a common pathway of apoptosis. This included the activation of interleukin 1 beta-converting enzyme (ICE)-like proteases with cleavage of the endogenous substrates poly(ADP ribose) polymerase and D4-GDI (GDP dissociation inhibitor for the rho family), as well as the fluorogenic peptide acetyl-Asp-Glu-Val-Asp-aminotrifluoromethylcoumarin (DEVD-AFC). The inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-fmk) successfully blocked this protease activity and prevented FAS-induced death but not BAX-induced death. Blocking ICE-like protease activity prevented the cleavage of nuclear and cytosolic substrates and the DNA degradation that followed BAX induction. However, the fall in mitochondrial membrane potential, production of reactive oxygen species, cytoplasmic vacuolation, and plasma membrane permeability that are downstream of BAX still occurred. Thus, BAX-induced alterations in mitochondrial function and subsequent cell death do not apparently require the known ICE-like proteases.