Abstract: The disclosure discloses a polymer represented by the general formula, wherein Rp is a residue of a polymer of a compound having a polymerizable unsaturated bond, Q is an organic residue of n+1 valences and connected directly or through another group to Rp by means of a single bond, Mk+ is a cation of k valence, Z is an organic function group capable of forming an ionic bond with cation Mk+ or an organic function group having a coordination capability with Mk+, and m, n and k are integers of one or more. The disclosure also discloses an intermediate of the polymer mentioned above.

Abstract: The present invention provides a method for inexpensively, easily and efficiently modifying the C-terminus of a protein or peptide; a method for easily and reliably isolating a C-terminal peptide fragment of a protein or peptide; and a method for rapidly, accurately and reliably determining an amino acid sequence of a protein or peptide by using a mass spectroscope. A method comprising the step of adding a formylation reagent and a catalyst to a protein or peptide to convert a carboxyl group into an aldehyde group. A method comprising the step of reacting a nucleophilic reagent with the aldehyde group to modify the C-terminus of the protein or peptide. A method comprising the step of reacting a support having a nucleophilic group to immobilize the protein or peptide. A method comprising the step of fragmenting the immobilized protein or peptide, washing the support, and isolating the C-terminal peptide fragment from the support.

Abstract: The present invention provides a method for effectively introducing sulfonic acid groups into the N-terminus of a protein or a peptide. The method comprises a modification step to react a N-terminus in a protein or peptide with a compound A which includes disulfide group and a cleavage step to cleave a disulfide bond of the disulfide group to convert into a sulfonic acid group. The present invention also provides a method of analyzing proteins or peptides easily and effectively on mass spectrometry and an intermediate that can be used to effectively derivatize proteins or peptides as sulfonic acid derivatives.

Abstract: The disclosure discloses a polymer represented by the general formula, Rp?Q?Z . . . Mk+)n]m, wherein Rp is a residue of a polymer of a compound having a polymerizable unsaturated bond, Q is an organic residue of n+1 valences and connected directly or through another group to Rp by means of a single bond, Mk+ is a cation of k valence, Z is an organic function group capable of forming an ionic bond with cation Mk+ or an organic function group having a coordination capability with Mk+, and m, n and k are integers of one or more. The disclosure also discloses an intermediate of the polymer mentioned above.

Abstract: A dental cement composition comprising an organic polymer and an inorganic powder including a polyvalent metal compound. The polymer comprises a unit (A) containing a (substituted) carboxyl group represented by a formula (I), and a unit (B) containing a (substituted) carbamoyl group represented by a formula (II). A sum of the units (A) and (B) accounts for at least 20 mol % of all units that form the organic polymer and a ratio of the unit (A)/unit (B) in the organic polymer is within a range from 0.6/1.0 to 1.0/0.6. When the quantity of the unit (A) or (B) having a smaller quantity than the other unit within the polymer is deemed 100 mol %, then in at least 70 mol % of the unit (A) or (B), carbons bonded to the (substituted) carboxyl group in the unit (A) and the (substituted) carbamoyl group in the unit (B) are either directly adjacent, or bonded together via a methylene group or ethylene group.

Abstract: The disclosure discloses a polymer represented by the general formula, wherein Rp is a residue of a polymer of a compound having a polymerizable unsaturated bond, Q is an organic residue of n+1 valences and connected directly or through another group to Rp by means of a single bond, Mk+ is a cation of k valence, Z is an organic function group capable of forming an ionic bond with cation Mk+ or an organic function group having a coordination capability with Mk+, and m, n and k are integers of one or more. The disclosure also discloses an intermediate of the polymer mentioned above.

Abstract: A simple and low-cost method of selectively modifying the C-terminal of a protein or peptide is provided. A method of modifying the C-terminal of a protein or peptide comprises forming an intramolecular oxazolone ring at the C-terminal of the protein or peptide that requires C-terminal modification, and then performing a ring-opening of the oxazolone ring to produce a protein or peptide with a modified C-terminal.

Abstract: A dental adhesive composition includes an organic polymer that contains a unit (A) containing a (substituted) carboxyl group, which is represented by formula (I), and a unit (B) containing a (substituted) carbamoyl group, which is represented by a formula (II). In the organic polymer, the sum of the two units (A) and (B) accounts for at least 20 mol % of all the units that constitute the organic polymer, and the ratio of unit (A)/unit (B) is within a range from 0.6/1.0 to 1.0/0.6. When the quantity of the unit having a smaller quantity than the other unit in the units (A) and (B) within the polymer is deemed 100 mol %, then in at least 70 mol % of the unit having a smaller quantity, the carbon bonded to the above (substituted) carboxyl group and the carbon bonded to the above (substituted) carbamoyl group are either directly adjacent, or bonded together via a methylene group or ethylene group.

Abstract: The present invention provides a method for selectively collecting the N-terminal peptide fragments of a protein of interest whether or not the protein of interest is modified on the N-terminus.

Abstract: The present invention provides a method for effectively introducing sulfonic acid groups into the N-terminus of a protein or a peptide; a method capable of analyzing proteins or peptides easily and effectively on mass spectrometry; an intermediate that can be used to effectively derivatize proteins or peptides as sulfonic acid derivatives. A method for derivatizing a protein or peptide to a sulfonic acid derivative, comprising steps of: modification step to react a N-terminus in a protein or peptide with a compound A which includes disulfide group, to obtain a protein or peptide modified with the compound A at the N-terminus; and cleavage step to cleave a disulfide bond of the disulfide group to convert into a sulfonic acid group, thereby converting the modified protein or peptide into a sulfonic acid derivative. A method for analyzing the amino acid sequence of a protein or peptide, wherein the sulfonic acid derivative of a protein or a peptide obtained by the above method is subjected to mass spectrometry.

Abstract: A simple and low-cost method of selectively modifying the C-terminal of a protein or peptide is provided. A method of modifying the C-terminal of a protein or peptide comprises forming an intramolecular oxazolone ring at the C-terminal of the protein or peptide that requires C-terminal modification, and then performing a ring-opening of the oxazolone ring to produce a protein or peptide with a modified C-terminal.

Abstract: The present invention provides a method for determining amino acid sequences of peptides involving the use of a mass spectrometer that not only offers a high decomposition efficiency into fragment ions and a high selectivity of cleavage sites for a wide variety of peptide including peptides of unknown identity, but also achieves highly sensitive, high-throughput detection of the resulting fragment ions. A method for determining amino acid sequence of a peptide, comprising the steps of: preparing a peptide of interest or fragments thereof obtained by optionally cleaving the peptide of interest; coupling an amino acid derivative to the N-terminus of the peptide of interest or the fragments thereof, the amino acid derivative having protected an amino group with a protective group and derived from an amino acid with a side chain containing an acidic group; and subjecting the coupled product to mass spectrometry analysis.

Abstract: The present invention provides a method for selectively collecting the N-terminal peptide fragments of a protein of interest whether or not the protein of interest is modified on the N-terminus.

Abstract: The present invention provides a novel metal complex useful for a reagent for determining the amino acid sequence of protein or peptide, and a method of using it for determining the amino acid sequence of protein or peptide. The metal complex which has a functional group capable of forming a covalent bond with the amino group of the N-terminal amino acid residue of protein or peptide or with the carboxyl group of the C-terminal amino acid residue of protein or peptide. In general, the functional group is in the ligand of the complex.

Abstract: The disclosure discloses a polymer represented by the general formula, 1