Lysosomal enzymes in human platelets

In human freshly prepared platelets the following lysosomal enzymes were studied: α‐mannosidase, α‐fucosidase, β‐galactosidase, β‐glucosidase, β‐glucuronidase, β‐ N ‐acetylglucosaminidase and acid phosphatase. For each of the examined enzymes the conditions providing maximal activity (pH, buffer), kinetic parameters (saturating substrate concentration and K m ) as well as heat stability were established. On the basis of these parameters it is suggested that many of the serum glycohydrolases may be platelet derived.