The Experts below are selected from a list of 63 Experts worldwide ranked by ideXlab platform
Hie-joon Kim - One of the best experts on this subject based on the ideXlab platform.
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Matrix-assisted laser desorption/ionization time-of-flight mass spectrometric observation of a peptide triplet induced by thermal cleavage of Cystine.
Rapid communications in mass spectrometry : RCM, 2001Co-Authors: Jong-seo Kim, Hie-joon KimAbstract:Heat-induced (90 °C, 30 min) β-elimination of a Cystine Residue leads to cleavage of a disulfide bond and produces a set of three peptides with a cysteine Residue, a thiocysteine Residue (+32Da), and a dehydroalanine Residue (−34Da). This characteristic feature was observed from somatostatin and insulin by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Mass spectrometric observation of this triplet is useful in identifying the presence of a Cystine Residue in a peptide, and could assist mass spectrometric identification of the peptide from a database. Copyright © 2001 John Wiley & Sons, Ltd.
Itaru Yazawa - One of the best experts on this subject based on the ideXlab platform.
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High throughput sequencing of cyclic peptide immobilized on a gel-type single bead
Amino Acids, 2016Co-Authors: Kiyoshi Nokihara, Takeshi Kasama, Yuki Tominaga, Atsushi Kitagawa, Akiyoshi Hirata, Takafumi Ohyama, Itaru YazawaAbstract:Relatively larger scale peptide libraries immobilized on a gel-type solid support consisting of 24 natural and non-natural amino acids by the “split and combine method” have been constructed to find interacting molecules. The diversity was ca. 200 millions of hexapeptides with cysteinyl Residues forming cyclotide. Selected beads after screening can be sequenced by the conventional Edman degradation, although several restrictions and the problems are known. To resolve these, a novel combinatorial method involving partial acid hydrolysis followed by liquid chromatography with on-line mass spectrometric analyses has been established. Problems were uncovered in an early stage of the process. Uncertain assignment caused by byproducts derived from a Cystine Residue and other materials could be resolved by optimal hydrolysis conditions and derivatization before mass spectrometric analysis. Discrimination between Leu and Ile could be performed using high energy collision induced dissociation in the high resolution MALDI-TOF-MS/MS. The present optimized protocol is useful for discovery of sequences of interacting molecules and a second library construction.
Jong-seo Kim - One of the best experts on this subject based on the ideXlab platform.
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Matrix-assisted laser desorption/ionization time-of-flight mass spectrometric observation of a peptide triplet induced by thermal cleavage of Cystine.
Rapid communications in mass spectrometry : RCM, 2001Co-Authors: Jong-seo Kim, Hie-joon KimAbstract:Heat-induced (90 °C, 30 min) β-elimination of a Cystine Residue leads to cleavage of a disulfide bond and produces a set of three peptides with a cysteine Residue, a thiocysteine Residue (+32Da), and a dehydroalanine Residue (−34Da). This characteristic feature was observed from somatostatin and insulin by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Mass spectrometric observation of this triplet is useful in identifying the presence of a Cystine Residue in a peptide, and could assist mass spectrometric identification of the peptide from a database. Copyright © 2001 John Wiley & Sons, Ltd.
Kiyoshi Nokihara - One of the best experts on this subject based on the ideXlab platform.
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High throughput sequencing of cyclic peptide immobilized on a gel-type single bead
Amino Acids, 2016Co-Authors: Kiyoshi Nokihara, Takeshi Kasama, Yuki Tominaga, Atsushi Kitagawa, Akiyoshi Hirata, Takafumi Ohyama, Itaru YazawaAbstract:Relatively larger scale peptide libraries immobilized on a gel-type solid support consisting of 24 natural and non-natural amino acids by the “split and combine method” have been constructed to find interacting molecules. The diversity was ca. 200 millions of hexapeptides with cysteinyl Residues forming cyclotide. Selected beads after screening can be sequenced by the conventional Edman degradation, although several restrictions and the problems are known. To resolve these, a novel combinatorial method involving partial acid hydrolysis followed by liquid chromatography with on-line mass spectrometric analyses has been established. Problems were uncovered in an early stage of the process. Uncertain assignment caused by byproducts derived from a Cystine Residue and other materials could be resolved by optimal hydrolysis conditions and derivatization before mass spectrometric analysis. Discrimination between Leu and Ile could be performed using high energy collision induced dissociation in the high resolution MALDI-TOF-MS/MS. The present optimized protocol is useful for discovery of sequences of interacting molecules and a second library construction.
H. M. Greven - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of fragments of arginine vasopressin and oxytocin containing a Cystine Residue in position 6
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: J. W. Van Nispen, J. A. J. Hannink, M. S. Schoffelmeer, W. P. A. Janssen, J. P. Polderdijk, H. M. GrevenAbstract:The synthesis is described of several fragments of the neurohypophyseal nonapeptide hormones arginine vasopressin and oxytocin. One group of fragments is characterized by the presence of an asymmetrical disulfide (a Cystine Residue in position 6), a second group consists of dimeric (symmetrical disulfides) fragments. As common intermediates, peptides containing an S-tritylcysteine Residue were synthesized by the fragment condensation approach. Treatment with methoxycarbonylsulfenyl chloride followed by reaction with the free thiol function of cysteine gave the asymmetrical disulfides, while treatment of the S-tritylcysteine containing peptide with iodine resulted in the corresponding dimers. Peptides with an N-terminal glutamine Residue (position 4) were found to convert spontaneously into the corresponding pyroglutamic acid products.
