A novel function by cathepsin D in degradation of nucleic acids.
Biochem Biophys Res Commun
; 682: 250-258, 2023 11 19.
Article
en En
| MEDLINE
| ID: mdl-37826948
ABSTRACT
Cathepsin D (CTSD) is an aspartic endopeptidase, however, we found that it was also capable of enzymatic digestion of nucleic acids (NAs). The purpose of this study was to investigate the basic properties of CTSD enzymatic activity on NAs, and explore the degradation mechanism. The results showed that NAs were efficiently digested between pH 3.0 and 5.0, and the optimum pH was 3.5. CTSD exhibited optimum activity at the temperature of 50°C. The degradation rate was improved with an increased CTSD concentration, and NAs were digested to an enzyme concentration of 0.001%, at which point, NAs were no longer digested. Ca2+ and Mg2+ at low concentrations of 5 mM promoted the digestion remarkably. As the protein substrate for CTSD, both Hb and BSA had no effect on DNA degradation, even when the molar ratio of proteinDNA was 1041. Kinetic parameters of Km and kcat/Km value were (42 ± 1) µM and (1.62 ± 0.1) × 10-2 s-1mM-1 respectively, using real-time quantitative PCR (RT-PCR). Specially, pepstatin A which is the specific aspartic protease inhibitor exhibited inhibitory effect on NA digestion by CTSD as well, suggesting that the catalytic active site of CTSD for NAs might be the same as protein. A brief degradation mechanism is discussed. The present study may change the cognition of CTSD specificity for substrate and contribute greatly to enzymology of CTSD.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ácidos Nucleicos
/
Catepsina D
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2023
Tipo del documento:
Article