Abstract: 0Type II collagen degradation is measurable using a sandwich immunoassay in which a single antibody specific for the amino acid sequence EKGPDP is used to form each side of antibody-collagen fragment-antibody sandwich complexes and the amount of said complexes is measured.

Abstract: Sandwich assays for collagen degradation products are conducted using an antibody of the same specificity on both sides of the sandwich or using a first antibody reactive with an epitope contained in the sequence EKAHDGGR and a second antibody which may be the same or different.

Abstract: This invention relates, in part, to a method of measuring the rate of degradation of collagen is disclosed which comprises determining the amount in a body fluid of one or more fragments of collagen having an amino acid sequence comprising isoaspartic acid. The invention also relates to an immunological binding partner that specifically binds to an amino acid sequence of type II collagen containing an isoaspartic acid residue. The invention further relates to a synthetic peptide having an amino acid sequence of type II collagen that contains an isoaspartic acid residue.

Abstract: Methods of characterizing the degradation of type II collagen in body fluids are disclosed. In a specific method, a sample of body fluid is subjected to at least two distinct immunological assays, each using a different immunological binding partner, and a numerical index is formed representing the difference in the results of the assays.

Abstract: A method of assaying collagen fragments in body fluids, including bringing a sample of body fluid in contact with at least one immunological binding partner for the collagen fragments, said binding partner being immunoreactive with synthetic peptides, the sequences of which are essentially derived from collagen and containing potential sites for cross-linking. The immunological binding partners are incorporated, either as whole antibodies or as immunologically active fragments thereof, in an assay for quantitative determination of collagen fragments in the sample. In addition to being contacted with the immunological binding partner(s), the sample may be brought into direct contact with the corresponding synthetic peptide. The invention further comprises a test kit and specific means for carrying out the method. The structure of specific peptides is also described.

Abstract: A method of assaying type II collagen fragments in body fluids, including bringing a sample of body fluid in contact with at least one immunological binding partner for the collagen fragments, said binding partner being immunoreactive with synthetic peptides, the sequences of which are essentially derived from collagen and containing potential sites for cross-linking. The immunological binding partners are incorporated, either as whole antibodies or as immunologically active fragments thereof, in an assay for quantitative determination of collagen fragments in the sample. In addition to being contacted with the immunological binding partner(s), the sample may be brought into direct contact with the corresponding synthetic peptide. The invention further comprises a test kit and specific means for carrying out the method. The structure of specific peptides is also described.

Abstract: The rate of degradation in vivo of a body protein is determined by measuring the amount of a D-amino acid containing fragment of the protein in a body fluid using an antibody capable of discriminating between the D-amino acid containing fragment and its L-amino acid containing analogue.

Abstract: The fragmentation pattern of collagen, especially of type 1, as reflected in breakdown products of collagen in a body fluid such as serum or urine is estimated by measuring the levels of such breakdown products using two or more distinct immunoassays. The results may be combined into a numerical index diagnostic of one or more pathological conditions or patient types.

Abstract: Type I collagen degradation products are assayed in a body fluid by conducting a competition immunoassay in which sample molecules compete with a peptide or isomerized peptide in binding to an immunological binding partner for the peptide or isomerized peptide respectively, wherein the peptide or isomerized peptide comprises the amino acids AHDGGR optionally extended at the N-terminal end with one or more amino acids that do not form a contiguous sequence with AHDGGR in type 1 collagen, and wherein D represents aspartic acid or .beta.-aspartic acid. The peptide C(X).sub.n AHDGGR, where X is any amino acid and n is preferably from 4 to 6 is provided for use in such assays and in diagnostic assay kits.

Abstract: Degradation of body proteins such as bone collagen is studied by detecting in body fluids isomerized peptide fragments of said proteins in which peptide bonding to the .alpha.-carboxylic acid group of aspartic acid or asparagine has become isomerized to an amide bond to the side chain carboxylic acid group of aspartic acid. Antibodies specific for the isomerized peptide sequences are used in assays.