Year: 1997
Type: dissertation
Abstract: HEMPAS (hereditary erythroblastic multinuclearity with positive acidified serum lysis test) is a rare congenital anemia. A group of enzymatic lesions affecting the biosynthesis of N-linked oligosaccharides has been reported in HEMPAS. This study was conducted to investigate the molecular basis of HEMPAS in a group of Ontario patients. Lectin binding and endoglycosidase digestions were utilized to determine the nature of abnormal oligosaccharides on two erythrocyte membrane glycoproteins, Bands 3 and 4.5. The results suggest a hybrid or high mannose N-glycan in place of poly N-acetyllactosamine on these proteins, consistent with a defect in $\alpha$-mannosidase II. A reduction in the enzymatic activities of GnT II or $\beta$4GalT, as reported in some HEMPAS patients, was not detected in the cultured EBV-transformed lymphoblasts of our patients. Moreover, poly N-acetyllactosamine was present on proteins in these cells. The alteration in the oligosaccharide moiety of Band 4.5 did not interfere with its glucose transport function.
Author: Homa Kameh
Language: Dutch
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2783279115