Immunohistochemical analysis of human skeletal muscle AMP deaminase deficiency. Evidence of a correlation between the muscle HPRG content and the level of the residual AMP deaminase activity.
We have previously described that, in healthy human skeletal muscle, an anti-histidine-proline-rich-glycoprotein (HPRG) antibody selectively binds to type IIB fibers that are well known to contain the highest level of AMP deaminase (AMPD) activity, suggesting an association of the HPRG-like protein to the enzyme isoform M. The present paper reports an immunohistochemical study performed on human skeletal muscle biopsies from patients with AMPD deficiency and carried out utilizing both the anti-HPRG antibody and an anti-AMPD antibody specific for the isoform M. A correlation between the muscle content of the HPRG-like protein and the level of AMPD activity was demonstrated. In the specimens from patients with Acquired AMPD deficiency the HPRG-immunoreactivity was less intense than that shown by the control subjects and was related to the residual AMPD activity. The patients affected by Primary and Coincidental AMPD deficiency, which were characterized by an absence of enzyme activity and AMPD immunoreactivity, showed the lowest HPRG immunoreactivity that was clearly detectable by Western blot analysis, but not by immunohistochemistry. The interpretation of the significance of these observations suggests a physiological mutual dependence between skeletal muscle HPRG and AMPD polypeptides with regard to their stability.
Dipartimento di Scienze dell'Uomo e dell'Ambiente, Chimica e Biochimica Medica, Università di Pisa, Via Roma 55, 56126 Pisa, Italy. a.raggi@med.unipi.it
Antonietta R M
AR
Sabbatini
Antonio
A
Toscano
Mohammed
M
Aguennouz
Daniela
D
Martini
Enza
E
Polizzi
Maria
M
Ranieri-Raggi
Arthur J G
AJ
Moir
Alba
A
Migliorato
Olimpia
O
Musumeci
Giuseppe
G
Vita
Antonio
A
Raggi
D000659:AMP Deaminase / Q000172:deficiency*; D000328:Adult; D000368:Aged; D000906:Antibodies; D000918:Antibody Specificity / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D009135:Muscular Diseases / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D010455:Peptides / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D000099053:Histidine-Rich Glycoprotein
D000906:Antibodies; D015415:Biomarkers; D010455:Peptides; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein; D000659:AMP Deaminase