Ribonuclease activity and substrate preference of human eosinophil cationic protein (ECP)

FEBS Letters

Sorrentino, Salvatore¹  Glitz, Dohn G.² 

[1] Dipartimento di Chimica Organica e Biologica, Universiteà di Napoli, I-80134 Napoli, Italy;Department of Biological Chemistry, UCLA School of Medicine, Los Angeles, CA 90024, USA

关键词: Eosinophil protein;    Helminthotoxin;    Neurotoxin;    Ribonuclease activity;    Ribonuclease superfamily;   

DOI  :  10.1016/0014-5793(91)80994-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The eosinophil cationic protein (ECP), a potent helminthotoxin with considerable neurotoxic activity, was recently shown to also have ribonucleolytic activity. In this work the substrate preference of ECP ribonuclease action was studied in detail. With single-stranded RNA or synthetic polyribonucleotide substrates ECP showed significant but low activity, 70- to 200-fold less than that of bovine RNase A. ECP hydrolyzed RNA more rapidly than it did any synthetic polynucleotide. Poly(U) was degraded more rapidly than poly(C), and poly(A) and double-stranded substrates were extremely resistant. Defined low molecular weight substrates in the form of the 16 dinucleoside phosphates (NpN′) and uridine and cytidine 2′, 3′-cyclic phosphates were tested, and none showed hydrolysis by ECP at a significant rate. The results link ECP ribonucleolytic activity to the ‘non-secretory’ liver-type enzymes rather than to the ‘secretory’ pancreatic-type RNases.

【 授权许可】

Unknown