Cathepsin D (CTSD)

Cathepsin D is a lysosomal aspartyl protease encoded by the CTSD gene and widely expressed in human tissues[1][6]. It is essential for intracellular protein degradation, activation of precursor proteins, and maintenance of proteostasis, particularly in post-mitotic cells such as neurons[4][5]. The mature enzyme is composed of heavy and light chains derived from a single precursor, with catalytic aspartic residues critical for activity[1][3]. Cathepsin D has well-established roles in protein turnover, autophagy, apoptosis, and neuronal health, and is implicated in cancer progression, neurodegenerative disorders, and lysosomal storage diseases[4][5][1]. It is a validated therapeutic target, with major pharmacological interest in selective inhibition, especially for cancer and neurodegenerative conditions. However, safety concerns arise from its involvement in essential cellular functions, making careful therapeutic targeting necessary[3][4].

Other names

Aspartyl proteaseLysosomal aspartyl proteaseEC 3.4.23.5Peptidase A1CatD

Reversible inhibition of protease activity (by pepstatin A and related compounds) Blockade of protein degradation within lysosomes Inhibition of amyloid precursor protein processing