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)

Cathepsin D was purified from ovaries of Xenopus laevis by both QAE-cellulose and pepstatin-Sepharose chromatography and then characterized and compared with Xenopus liver cathepsin D. Ovary cathepsin D appeared predominantly as a 43-kilodalton (kDa) molecular mass, as revealed by SDS-polyacrylamide gel electrophoresis, whereas the liver enzyme was obtained exclusively as a 36-kDa protein. The purified 43-kDa ovary enzyme cleaved vitellogenin limitedly to produce yolk proteins at pH 5.6. The specific activity of ovary cathepsin D was five to six times lower than that of the liver enzyme, as measured by hemoglobin-hydrolysis at pH 3, but the ovary enzyme was shown to be superior to the liver enzyme in terms of vitellogenin-cleaving activity, as examined at pH 5.6. Ovarian enzyme preparations contained variable amounts of 36-kDa species; this form was considered to be an autolytic product of the 43-kDa form arising during purification, because it was not detected in oocyte extracts but was generated by incubation of the purified 43-kDa enzyme alone in an acid solution. The conversion of the 43-kDa form by hepatic factors was accompanied by a marked increase in hemoglobin-hydrolytic activity.
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PMID:Vitellogenesis-related ovary cathepsin D from Xenopus laevis: purification and properties in comparison with liver cathepsin D. 892 51

Monoclonal antibody (mAb) fragmentation is a well-known degradation pathway that results in product loss and can significantly impact product quality, efficacy, or even cause immunogenic reactions, thus potentially endangering patients' health. It is recognised that residual proteases present among host cell proteins (HCPs) such as those expressed by Chinese Hamster Ovary (CHO) can induce fragmentation, and failure of their complete removal during downstream processing could cause fragmentation during mAb production and in the final drug product. We identified, using a protease inhibitor screen, an aspartic protease that contributes to proteolytic fragmentation of partially purified mAbs in multiple projects. Subsequent LC-MS analysis indicated that cathepsin D, a typical aspartic protease, was responsible for the observed fragmentation of in-process samples. To address the issue, an alternative chromatography wash was implemented at the capture step and has been demonstrated to be an effective and scalable solution to mitigate the residual cathepsin D associated fragmentation risk. Furthermore, a near real time targeted mass spectrometry method has been developed to proactively monitor the presence of cathepsin D during upstream and downstream process. Our approach demonstrated an emerging HCP mitigation strategy through integrated upstream and downstream involvement and holds great promise for a range of future applications.
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PMID:Cathepsin D: Removal strategy on protein A chromatography, near real time monitoring and characterisation during monoclonal antibody production. 3144 1