Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.27 (thermolysin)
 1,894 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied susceptibility of basement membranes in a variety of tissues to solubility in guanidine hydrochloride and to proteolytic degradation by trypsin and thermolysin. Unfixed sections from embryonic and adult mouse tissues and the EHS tumor were subjected to solvent buffers or digested with enzymes. The retention or disappearance of the basement-membrane components nidogen, laminin, collagen IV, and heparan sulfate proteoglycan was subsequently assayed by immunofluorescence. Our data showed that in all tissues nidogen was the most readily solubilized component and the most susceptible to proteolytic degradation. With few exceptions, nidogen in embryonic tissues was more susceptible to degradation than that in adult tissues, and this correlated well with the susceptibility of the other basement-membrane components to be degraded. We conclude that basement membranes differ quite markedly in their solubility and their susceptibility to proteolytic degradation and that these properties reflect differences in their molecular structure.
 ...
PMID:Differences in the solubility and susceptibility to proteolytic degradation of basement-membrane components in adult and embryonic mouse tissues. 252 98

We have characterized an in vitro skin model consisting of neonatal keratinocytes and fibroblasts grown on a nylon mesh. To produce a dermal model, fibroblasts were seeded onto nylon mesh and grown for 4 weeks until a physiologic dermal-like matrix was formed. This matrix was found to consist of collagens I and III, fibronectin, and glycosaminoglycans. Keratinocytes were then seeded onto the dermal model and the co-culture was grown at the air/liquid interface. A differentiated epidermis with distinct basal, spinous, granular, and stratum corneum layers was formed. When incubated in the presence of keratinocytes, fibronectin immunofluorescence increased throughout the dermis compared to cultures incubated similarly in the absence of keratinocytes. A basement membrane zone rich in laminin, collagen IV, and heparan sulfate proteoglycan was detected. The epidermis, isolated from the co-culture by thermolysin digestion, was analyzed for differentiation markers. K1 keratin (67-kDa) and involucrin were detected by immunologic techniques. Ceramide lipids (types III and IV), thought to be important in barrier function, were detected by thin-layer chromatography. The permeability of the co-culture to a panel of compounds, including [3H]-water, was determined using Franz and side-by-side diffusion cells. The permeability coefficient for water was of the same order of magnitude as that determined for neonatal foreskin. The co-culture also showed selective permeability to a panel of compounds of differing lipid solubility. This co-culture metabolized [3H]-testosterone to a profile of metabolites similar to that of neonatal foreskin. We believe that this in vitro skin model will be useful for the study of drug permeability and metabolism.
 ...
PMID:Characterization, barrier function, and drug metabolism of an in vitro skin model. 842 93