Proteolytic processing of von Willebrand factor subunit: Heterogeneity in type-IIA von Willebrand disease
| Autor: | M. F. López Fernández, J. Lasierra, B. Justiça, A. F. Villamor, J. L. Navarro, J. Batlle, A. Pardo, Michael Campos |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Blood Platelets
congenital hereditary and neonatal diseases and abnormalities medicine.medical_specialty Macromolecular Substances Protein subunit Pathogenesis Von Willebrand factor hemic and lymphatic diseases Internal medicine Endopeptidases von Willebrand Factor Von Willebrand disease medicine Coagulopathy Humans Deamino Arginine Vasopressin Platelet Desmopressin Hematology biology Chemistry General Medicine medicine.disease Peptide Fragments Molecular Weight von Willebrand Diseases Endocrinology biology.protein Female circulatory and respiratory physiology medicine.drug |
| Zdroj: | Annals of Hematology. 68:111-115 |
| ISSN: | 1432-0584 0939-5555 |
| DOI: | 10.1007/bf01727414 |
| Popis: | Type IIA von Willebrand disease (vWD) is a heterogeneous disorder for which two different pathogenetic mechanisms have been proposed: increased proteolytic susceptibility of von Willebrand factor (vWF), and/or interference of its post-translational processing. Subunit analysis of vWF in type-IIA vWD has revealed an increased relative proportion of the 176- and 140-kDa subunit-derived fragments, suggesting an augmented fragmentation of vWF, even in the resting state. We analyzed the subunit pattern of vWF in plasma from five previously described patients with type-IIA vWD. All of them showed the above-mentioned pattern. In addition, the presence of a new band with an apparent molecular mass of 200 kDa, not described in normal individuals or in patients with vWD, was repeatedly observed in one of these patients. This patient also exhibited an abnormal vWF multimeric structure in platelets and in plasma, before and after desmopressin administration, when the blood was collected either in the presence or in the absence of proteinase inhibitors. We believe that an abnormal primary structure of vWF could be responsible for this abnormal proteolytic fragmentation pattern, as well as for the abnormal multimerization of vWF. Moreover, an abnormal susceptibility to proteolysis appears to be present, as suggested by the increase in the relative proportion of the 176-kDa fragment observed in the same patient. Future sequencing studies and genetic analysis may clarify whether there are one or two different defects related to the vWF of that patient. Our results indicate that the subunit analysis of vWF may reveal additional defects present in type-IIA vWD that may help our understanding of the pathogenesis of such disease. |
| Databáze: | OpenAIRE |
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