Some enzymatic activities have been assayed in the gastrocnemius muscle of patients with obstructive arteriopathy of the lower limbs. The specific activities of all the examined glycolytic enzymes, of malate dehydrogenase and of glycerol-3-phosphate dehydrogenase are significantly decreased while the specific activities of two lysosomal enzymes, beta-glucuronidase and cathepsin A, are significantly higher than in the controls. Therefore it may be inferred that the metabolic capacity of glycolysis and of Krebs cycle are lowered. On the other hand the increased specific activity of lysosomal enzymes suggests the hypothesis that the above mentioned modifications and the morphologic alterations of the muscle and of the small blood vessels might be ascribed, at least partly, to a release of lysosomal hydrolases in active form.

Adult↗

PubMedDate not supplied

Horse muscle acylphosphatase: a more rapid purification procedure and crystallization.

A crystalline acyl phosphatase has been obtained from horse muscle. The enzyme purified by a modified procedure which allowed to obtain a larger yield with respect to a method previously developped in this laboratory, was homogeneous by disc electrophoresis on polyacrylamide gel. Crystals of this enzymatic protein have been obtained by the addition of ammonium sulphate to around 52% saturation.

Acid Anhydride Hydrolases↗

PubMedDate not supplied

The complete amino acid sequence of bovine skeletal muscle acylphosphatase.

The primary structure of bovine skeletal muscle acylphosphatase was determined by performing the sequence analyses of the complete series of tryptic peptides. The amino acid composition of the entire series of peptic peptides was used to reconstruct the sequence by the overlapping method. The proposed structure is further confirmed by analogy with known amino acid sequences of acylphosphatase from skeletal muscle of other vertebrate species. The length of the polypeptide chain is 98 residues, identical to the length of the enzymes from other known mammalian species, but different from that found in turkey. The enzyme is NH2-acetylated and a comparison with the analogous molecular forms from other vertebrate species indicates that there are several long polypeptide stretches strictly conserved (93-97% identical position among mammals, and about 80% between calf and turkey enzymes).

Acid Anhydride Hydrolases↗

PubMedDate not supplied

Quantitative determination of acylphosphatase levels in horse tissues by enzyme-linked immunosorbent assay.

A non competitive enzyme-linked immunosorbent assay (ELISA) specific for horse muscle acylphosphatase (E.C. 3.6.1.7.) has been developed. The purified anti-acylphosphatase antibodies were immobilized by passive absorption to a solid-phase support and incubated with known and unknown amounts of antigen. The antibody-acylphosphatase complex was quantified using the same antibody conjugated to horseradish peroxidase. The assay yields positive reactions with as little as 0.05 ng of antigen, with intra- and interassay coefficients of variation of 5% and 7%, respectively. On the basis of this assay we developed a more sensitive test than the optical one, using benzoyl-phosphate as substrate, for acylphosphatase determination. By means of this test, the presence of the enzyme in horse tissue homogenates was evaluated under conditions in which the optical test failed to distinguish the acylphosphatase activity from that of other enzymes.

Acid Anhydride Hydrolases↗

PubMedDate not supplied

Turkey muscle acylphosphatase: purification and comparative studies.

Turkey muscle acylphosphatase is strongly bound to anti-(horse muscle acylphosphatase ) antibodies covalently linked to an agarose resin. This permits use of an affinity chromatography step in the purification, which increased the final yield and allowed us to isolate three different molecular forms of the enzyme. Form 1 is a mixed disulfide between the polypeptide chain and glutathione; form 3 is an S-S dimer of the polypeptide chain present in form 1, while form 2, present in a very low amount, consists of a polypeptide chain quite similar in aminoacid composition to that found in form 1. The three molecular forms show very similar kinetic parameters. The comparison of these molecular forms with those isolated from horse muscle showed similar kinetic properties but different structural features.

Acid Anhydride Hydrolases↗