Chromogenic substrates in haemostasis.
Advances in knowledge of the structure-function relationships of the proteins involved in haemostatic pathways, have made it possible to synthesize small peptides which mimic the active site of many of the serine proteases concerned. Attachment to the cleavage site of such synthetic peptides, of a detector molecule such as para-nitroaniline which, when released, produces a coloured compound has enabled many of the enzyme reactions of haemostasis, and most of the co-factors and naturally-occurring inhibitors, to be individually and sensitively quantitated. Chromogenic substrate assays are very specific and overcome the criticism levelled at many conventional assays that, being based on the speed of formation or the rate of destruction of a fibrin clot, they frequently involve enzymatic reactions in addition to that being examined. Moreover, chromogenic substrate assays are generally simple and quick to perform and are readily automated. They are thus economical of manpower and, more importantly from the point of view of patient care, they permit the rapidly-changing status of those with acute derangements of haemostasis to be monitored more frequently and comprehensively than is possible using some conventional assays. Chromogenic substrate assays have some limitations, however. Since they mimic only a small portion of the natural substrate, they may not be sensitive to structural defects elsewhere in the molecule, and may thus not totally reflect biological activity. Though technically simple to perform, the defined incubation times and temperatures must be rigidly adhered to if reliable results are to be obtained.(ABSTRACT TRUNCATED AT 250 WORDS)
Hutton
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RA
Katharine Dormandy Haemophilia Centre, Academic Department of Haematology, Royal Free Hospital, London.
D002863:Chromogenic Compounds; D006487:Hemostasis; D006801:Humans
D002863:Chromogenic Compounds