Abstract: Peptide sequences consisting of 2-4 amino acids with high affinity and comparatively high specificity to a number of various, physiologically important proteases are known to have been synthetized before. Such sequences with an added C-terminal marker have been widely used as substrates for the quantitative determination of the kind of proteases mentioned above. The method is based on the fact that the marker is split off under influence of the enzyme and that the liberated marker possesses an easily measurable, for instance, optic property which differs from that of the original substrate. The type of markers used until today have mainly been chromophores or fluorophores which can be quantified by photometry or fluorometry.The present invention relates to a new type of markers coupled to known peptide sequences. These markers are luminol or isoluminol which in their free state can be brought to luminate intensely, but lose considerably in luminescence when they are amide-bound to a peptide sequence.

Abstract: Easily split enzyme substrates for the quantification of proteases having the general formulaR.sub.1 --p-Glu--A.sub.1 --A.sub.2 --NH--R.sub.2,whereR.sub.1 =H or a protective group, preferably t-butyloxycarbonyl, benzyloxycarbonyl;A.sub.1 =Gly, Ala, Val, Leu, Ile, Ser, Thr, Pro, Pip, Phe or Tyr;A.sub.2 =Arg or Lys;R.sub.2 =an aromatic, possibly substituted, hydrocarbon group, wherein --NH--R.sub.2 is a physico-chemically determinable group, preferably a chromogenic or fluorogenic group which is split by a present enzyme and then forms a cleavage product of the formula H.sub.2 N--R.sub.2 the amount of which can be quantified.Processes for the production of said substrates. Method in the laboratory diagnostics of proteases using said substrates.

Abstract: Easily split enzyme substrates for the quantification of proteases having the general formulaR.sub.1 --p-Glu--A.sub.1 --A.sub.2 --NH--R.sub.2,whereR.sub.1 =H or a protective group, preferably t-butyloxycarbonyl, benzyloxycarbonyl;A.sub.1 =Gly, Ala, Val, Leu, Ile, Ser, Thr, Pro, Pip, Phe or Tyr;A.sub.2 =Arg or Lys;R.sub.2 =an aromatic, possibly substituted, hydrocarbon group, wherein --NH--R.sub.2 is a physico-chemically determinable group, preferably a chromogenic or fluorogenic group which is split by a present enzyme and then forms a cleavage product of the formula H.sub.2 N--R.sub.2 the amount of which can be quantified.Processes for the production of said substrates. Method in the laboratory diagnostics of proteases using said substrates.

Abstract: Serine proteases in a substance such as blood are determined by contacting the substance with a novel chromogenic or fluorgenic substrate for serine proteinases and spectrophotometrically measuring the quantity of a chromophore or fluorescent compound released from the substrate by serine proteases in the substance. The novel substrate has the amino acid sequence-ILe-A-Gly-Arg-wherein A is Asp or Glu substituted in the carboxylic group by esterification or amidation. The novel substrate increases sensitivity and accuracy of the determination.

Abstract: New chromogenic substrates suitable for serine proteases, specially suitable for diagnostic determination of factor Xa, which are represented by the following formula:R.sub.1 -A.sub.1 -A.sub.2 -Gly-Arg-NH-R.sub.2or its salts, where R.sub.1 is selected from the group of hydrogen, alkanoyl having from 1 to 12 carbon atoms, cyclohexylcarbonyl, benzoyl, benzoyl substituted with one or two halogen atoms, methylamine or phenyl groups, benzene sulphonyl and toluenesulphonyl; R.sub.2 is a chromophoric group; A.sub.1 is selected from the group of a single bond, and the amino acids selected from the group of Gly, Ala, Val, Leu, Ileu, Pro, Met, Phe and Tyr; and A.sub.2 is selected from the group of the amino acids Glu, Gln, Asp, and Asn.

Abstract: A chromogenic substrate having the formula ##STR1## and salts thereof wherein R.sub.1 is H or OH, R.sub.2 is a chromophoric group, and n is 1, 2 or 3.

Abstract: Method for the quantitative determination of serine proteases which includes contacting the substance for which the determination is desired with a diagnostically active chromogenic substrate with good stability and high specificity to serine proteases having the formula: H--D--A.sub.1 --A.sub.2 --A.sub.3 --NH--R or salts thereof, wherein A.sub.1 is Gly, Ala, Val, Leu, Ile, Pip, Pro, or Aze; A.sub.2 is Gly, Ala, Val, Leu, Ile, Pip, Pro, Aze, or Phe; A.sub.3 is Arg, Lys, or Orn, and R is a chromophoric group.

Abstract: Chromogenic or fluorogenic enzyme substrates for serine proteases containing the amino acid sequence Ile-A-Gly-Arg wherein A is Asp or Glu substituted in the carboxylic group by esterification or amidation, a method of preparation thereof, and use thereof.

Abstract: Process for determining thrombin and thrombin-like enzymes employing a substrate having the formula: ##STR1## and salts thereof, wherein R.sub.1 is H or OH; R.sub.2 is a chromophoric group; the N-terminal amino acid is in the D configuration and n is 1, 2 or 3 provided along with the method of use.

Abstract: The proteolytic enzyme designated as factor Xa is diagnostically determined by contacting the enzyme with a chromogenic substrate represented by the formulaR.sub.1 -A.sub.1 -A.sub.2 -Gly-Arg-NH-R.sub.2or its salts, where R.sub.1 is hydrogen or alkanoyl having from 1 to 12 carbon atoms or cyclohexylcarbonyl or benzoyl or benzoyl substituted with one or two halogen atoms, methylamine or phenyl groups or benzene sulphonyl or toluenesulphonyl, R.sub.2 is nitrophenyl or naphthyl or nitronaphthyl or methoxynaphthyl or quinolyl or nitroquinolyl, A.sub.1 is a single bond or one of the amino acids Gly, Ala, Val, Leu, Ileu, Pro, Met, Phe or Tyr, and A.sub.2 is one of the amino acids Glu, Gln, Asp, or Asn and spectrophotometrically measuring the degree of enzymatic hydrolysis.

Abstract: Diagnostically active chromogenic substrate with good stability and high specificity to serine proteases having the formula: H-D-A.sub.1 -A.sub.2 -A.sub.3 -NH-R or salts thereof, wherein A.sub.1 is Gly, Ala, Val, Leu, Ile, Pip, Pro, or Aze; A.sub.2 is Gly, Ala, Val, Leu, Ile, Pip, Pro, Aze, or Phe; A.sub.3 is Arg, Lys, or Orn, and R is a chromophoric group.