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)

Two lambda gt11 libraries containing complementary DNAs from human breast cancer MCF7 cells were screened by expression with monoclonal antibodies to the secreted 52K protein and with a 36-mer oligonucleotide derived from the N-terminal amino acid sequence of the secreted 52K protein. Four overlapping clones were sequenced, and found to be extensively homologous to the cathepsin D of normal human kidney, except for 5-point mutations resulting in one amino acid change (Ala to Val) in the profragment of cathepsin D. Northern blot analysis showed the 2.2 kilobase (kb) cathepsin D mRNA to be induced by estradiol in MCF7 cells and produced constitutively at high levels in the estrogen-receptor-negative BT20 cell line. A simple restriction pattern consistent with the restriction map of cathepsin D cDNA was obtained in Southern blot analysis of MCF7 cell DNA. In situ hybridization of the 52K-9 cDNA probe on normal lymphocytes assigned the 52K cathepsin D gene at the extremity of the short arm of chromosome 11, in the p15 band, close to the H-ras gene and in the region whose deletion increases the risk of invasive breast cancer. We conclude that the estrogen induced 52K protein has the same sequence as normal pro-cathepsin D and we propose that the 52K protein correspond to the only pro-cathepsin D expressed in MCF7 cells.
 ...
PMID:Cloning and sequencing of the 52K cathepsin D complementary deoxyribonucleic acid of MCF7 breast cancer cells and mapping on chromosome 11. 339 49

Selective inhibition of enzymes involved in antigen processing such as cathepsin E and cathepsin D is a valuable tool for investigating the roles of these enzymes in the processing pathway. However, the aspartic protease inhibitors, including the highly potent pepstatin A (PepA), are inefficiently transported across the cell membrane and thus have limited access to antigen processing compartments. Previously described mannose-pepstatin conjugates were efficiently taken up by the cells via receptor mediated uptake. However, cells without mannose receptors are unable to take up these conjugates efficiently. The aim of the present study was to synthesize new cell-permeable aspartic protease inhibitors by conjugating pepstatin A with well-known cell penetrating peptides (CPPs). To achieve this, the most commonly used CPPs namely pAntp(43-58) (penetratin), Tat(49-60), and 9-mer of l-arginine (R9), were synthesized and coupled to pepstatin. The enzyme inhibitory properties of these bioconjugates and their cellular uptake into MCF7 (human breast cancer cell line), Boleths (EBV-transformed B-cell line) and dendritic cells (DC) were the focus of our study. We found that the bioconjugate PepA-penetratin (PepA-P) was the most efficient cell-permeable aspartic protease inhibitor tested, and was more efficient than unconjugated PepA. Additionally, we found that PepA-P efficiently inhibited the tetanus toxoid C-fragment processing in peripheral blood mononuclear cells (PBMC), primary DC and in primary B cells. Therefore, PepA-P can be used in studying the role of intracellular aspartic proteases in the MHC class II antigen processing pathway. Moreover, inhibition of tetanus toxoid C-fragment processing by PepA-P clearly implicates the role of aspartic proteinases in antigen processing.
 ...
PMID:A novel cell penetrating aspartic protease inhibitor blocks processing and presentation of tetanus toxoid more efficiently than pepstatin A. 1793 27