Studies on normal and mutant cystathionine beta-synthase from cultured skin fibroblasts.

Samples (2ml) of a 605g,,. supernatant were applied to continuous linear gradients of 0.74-2.45 M-sucrose in 16 ml, on a cushion of 2ml of 2.45 M-sucrose. Centrifugation was at 4°C in a 3 x25ml swing-out rotor, and the integrated field-time was 562000g-min at ray. 9.39cm. Fractions (1 ml) were collected by displacement with 2.45~-sucrose. The letters A-D indicate the positions of the four fractions showing peaks of marker enzyme activity. Fractions are numbered from the low-density end of the gradient (0) Protein; (6) acid phosphatase; (c) alkaline phosphatase; ( d ) N-acetyl-b-glucosaminidase; (e) peroxidase; ( f ) collagenolytic cathepsin.