Acid maltase

Eleven defects in the metabolism of glycogen have been reported nine of them affect skeletal muscle directly (see Figure 5), but only glycogenosis type II (acid maltase deficiency) and glycogenesis type V (myophosphorylase deficiency) are reasonably common the rest are rare and some have been recorded in isolated case studies only. 

Figure 6. Glycogen storage in acid maltase (AM) deficiency in this late-onset case not all muscle fibers are affected.

Type II Pompe s disease Deficiency of lysosomal a-1 4- and 1 ->6-glucosldase (acid maltase) Fatal, accumulation of glycogen in lyso-somes, heart failure. 

Martiniuk, F., Chen, A., Donnabella, V. et al. (2000) Correction of glycogen storage disease type II by enzyme replacement with a recombinant human acid maltase produced by over-expression in a CHO-DHFR(neg) cell line. Biochemical and Biophysical Research Communications, 276 (3), 917-923. 

Human creatine kinase -MM MAK33 IgGl Cardiac disease, mitochondrial disorders, inflammatory myopathies, myasthenia, polymyositis, McArdle s disease, NMJ disorders, muscular dystrophy, ALS, hypo and hyperthyroid disorders, central core disease, acid maltase deficiency, myoglobinuria, rhabdomyolysis, motor neuron diseases, A. thaliana A. thaliana 2S2 seed storage protein SP + 0.02-0.4% TSP of fresh leaf extract (10-12% TSP of intercellular fluid) 52... 

An additional cause of weakness may be involvement of the anterior horn cells of the spinal cord, which is very conspicuous in infantile acid maltase deficiency. All three glycogenoses causing weakness are in fact due to generalized enzyme defects, but histological signs of denervation are not evident. 

AMD (i) acid maltase deficiency (ii) age-related macular CAT computer assisted tomography... 

Bodamer, O. A., Leonard, J. V. and Halliday, D. (1997). Dietary treatment in late-onset acid maltase deficiency. Eur. J. Pediatr. 156(Suppl. 1), S39-S42. 

Lin, C. Y., Ho, C. H., Hsieh, Y. H. and Kikuchi, T. (2002). Adeno-associated virus-mediated transfer of human acid maltase gene results in a transient reduction of glycogen accumulation in muscle of Japanese quail with acid maltase deficiency. Gene Ther. 9, 554-563. 

Martiniuk, F., Chen, A., Mack, A., Donnabella, V., Slonim, A., Bulone, L., Arvanitopoulos, E., Raben, N., Plotz, P. and Rom, W. N. (2002). Helios gene gun particle delivery for therapy of acid maltase deficiency. DNA Cell Biol. 21, 717-725. 

II Acid maltase Pompe s disease Muscle weakness death by age 2 years (infantile variant)... 

Almost all enzymes show a high degree of optical specificity. Thus, there are certain enzymes which catalyse the hydrolysis of same group of substances possessing same optical activity i.e., D-amino acid oxidase acts on D-amino acid and L-amino acid oxidase acts on L-amino acid. Maltase catalyses the hydrolysis of a-but not p- glycosides. 

T-tubule system in skeletal muscle fibers Late onset acid maltase defiency in man Tubular network 0 [96]... 

GSD type II, Pompe s disease Deficiency of acid maltase causes excess glycogen accumulation in lysosomes. See text. 

Amato A A (2000). Acid maltase deficiency and related myopathies. Neurol. Clin. 18(1) 151-165. 

The isoenzymes of a-D-glucosidases have been studied in human white blood cells by immunological and electrophoretic techniques.Three isoenzymes have been found in leucocyte extracts lysosomal a-D-glucosidase ( acid maltase, glucoamylase), cytoplasmic neutral oi-D-glucosidase, and an enzyme immuno-logically identical to renal maltase (a-D-glucosidase). In Pompe s disease and other types of acid maltase deficiency, the deficiency is as complete in leucocytes as in other tissues, and the residual activity is due to renal maltase . 

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