Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA clone containing the entire coding region for bovine pre-alpha-lactalbumin (LA) together with 27 base pairs of 5'-noncoding and 268 base pairs of 3'-noncoding sequences was isolated from a bovine mammary cDNA plasmid library in the Okayama-Berg vector system using a synthetic oligonucleotide probe and sequenced. The coding segment for mature LA was subcloned into the T7 expression system of Studier and co-workers (Studier, F.W., and Moffatt, B.A. (1986) J. Mol. Biol. 189, 113-130; Rosenberg, A.H., Lade, B.N., Chui, D.S., Lin, S.W., Dunn, J.J., and Studier, F.W. (1987) Gene (Amst.) 56, 125-135) and expressed as a 21-kDa fusion protein that consisted of the mature bovine LA sequence connected to the NH2-terminal 50 residues of human cathepsin D by a linker sequence containing protease cleavage sites. This fusion protein was expressed in an insoluble form and accumulated to about 50% of the total bacterial protein within 3 h after induction of T7 RNA polymerase synthesis. The protein was solubilized, purified by gel filtration, and converted to an active form by treatment with mixtures of reduced and oxidized glutathione in the presence of Ca2+. The maximum specific activity of the fusion protein was about 25% of that of native LA, suggesting that the attachment of an NH2-terminal extension sterically hinders but does not prevent the interaction with galactosyltransferase. The extension also does not block the binding of the regulatory Ca2+ ion that is required for folding from the reduced denatured state. Trypsin cleaved the folded fusion protein specifically at a Lys-Glu bond at the junction with the mature LA sequence to give a product indistinguishable in structure and activity from native LA.
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PMID:Recombinant bovine alpha-lactalbumin obtained by limited proteolysis of a fusion protein expressed at high levels in Escherichia coli. 268 74

Hydrolysis of histones by proteinases from rat liver, skin and other sources was studied by using a rat thymus histone preparation as the substrate and polyacrylamide-gel electrophoresis and densitometric analysis as the methods to detect histone subtypes and their hydrolysis. The rat mast-cell proteinase I effectively hydrolysed histones except type H4. Thrombin hydrolysed effectively histones H1 and H2A, whereas plasmin hydrolysed all types of histones. Cathepsin D hydrolysed especially histone H2A. Cathepsins B and L hydrolysed all histones more slowly, and cathepsin H hydrolysed them extremely slowly. Epidermal aminoendopeptidase did not hydrolyse histones. Trypsin and chymotrypsin were used as reference enzymes, which hydrolysed all types of histones in very low concentrations. This study suggests that a variety of proteinases could play a role in histone hydrolysis. Hydrolysis of a specific subtype of histones, such as histone H2A at pH 6 by cathepsin D, may be directly involved in regulation of epidermal-cell differentiation.
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PMID:Hydrolysis of histones by proteinases. 296 88

Trypsin inhibitor was isolated from the vegetative portion of alfalfa and purified 270-fold by affinity chromatography on Trypsin-Sepharose. The inhibitor was eluted by gel-filtration as a single peak with molecular weight of 6900. Disc-electrophoresis of the purified inhibitor revealed the presence of only one protein band. Trypsin inhibition is a mixed process. The trypsin inhibitor from alfalfa does not prevent the activity of cathepsin D from bovine brain. Trypsin inhibitor was immobilized on BrCN-activated Sepharose 4B. The binding of trypsin to the immobilized trypsin inhibitor was studied: 5 mg of the immobilized trypsin inhibitor were found to bind 1 mg of trypsin.
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PMID:[Purification and properties of inhibitor from vegetative portion of alfalfa]. 727 46

Digestive endoprotease activities of the rice water weevil, Lissorhoptrus brevirostris Suffrian (Coleoptera: Curculionidae), were characterized based on the ability of gut extracts to hydrolyze specific synthetic substrates, optimal pH, and hydrolysis sensitivity to protease inhibitors. Larvae of this species were found to use a complex proteolytic system that includes cathepsin D-, cathepsin B-, trypsin-, and chymotrypsin-like activities. Trypsin-like activity was evenly distributed among the anterior, middle, and posterior portions of the gut, whereas cathepsin B- and cathepsin D-like activities were mainly located in the anterior and middle sections, and the chymotrypsin-like activity was highest in the middle and posterior sections. Gelatin-containing native-PAGE gels indicated the presence of several aspartyl, cysteine, and serine protease forms and confirmed the spatial organization of the proteolytic digestive process.
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PMID:Proteolytic gut activities in the rice water weevil, Lissorhoptrus brevirostris Suffrian (Coleoptera: Curculionidae). 1270 Nov 11