It is not yet clear whether lysosomal enzymes act only in degenerative processes, in response to noxious stimuli, or whether they act in the normal degradative processes of turnover. In support of the latter belief is the observation that specific lysosomal enzymes are absent (or highly deficient) in certain genetic lesions characterized by accumulation of the intermediates on which they act 6,...

Homogenates from 5 species of Trypanosomatids were screened for the presence of a series of acid hydrolases. The insect flagellae, Crithidia sp., contains 5 enzymes reminiscent of plant parasitism, which were absent from or of very low specific activity in parasites of the genera, Trypanosoma and Leishmania. The latter mammalian parasites, on the other hand, exhibited higher acid proteinase and...

UDP-glucose hydrolases are a group of relatively little known membrane-bound or periplasmic enzymes found in Salmonella enterica and E. coli. UDP-glucose is an agonist for a specific P2 receptor (P2Y14) found on epithelial cells and cells associated with innate immunity. It is also recognised as a ‘danger signal’. Cells respond to mechanical damage by releasing UDP-glucose which activates P2Y14...

The existence of intracellular particles with sedi-mentation characteristics intermediate between those of mitochondria and microsomes has been demonstrated in liver by studies of enzyme distribution among subcellular fractions (1-3), and the postulated intermediary particles were named "lysosomes" because of their manifold hydrolytic properties (1). The electron microscope shows that this inte...

The large HAD (haloacid dehalogenase) superfamily of hydrolases comprises P-type ATPases, phosphatases, epoxide hydrolases and L-2-haloacid dehalogenases. A comparison of the three-dimensional structure of L-2-haloacid dehalogenase with that of the response regulator protein CheY allowed the assignment of a conserved pair of aspartate residues as the Mg2+-binding site in the P-type ATPase and p...

Two isolates of Trichoderma, which reduce the incidence of witches’broom disease caused in cocoa by Crinipellis perniciosa, were evaluated for their potential to produce hydrolases in liquid medium. Very low or no hydrolytic activity was produced in the absence of any substrate. The activities of chitinase, N-acetylglucosaminidase, β-1,3-glucanase, total cellulase, endoglucanase, arylβ-glucosid...