The antiviral activity of ribosomal polynucleotides against encephalomyocarditis virus infection of mice

Abstract

Intraperitoneal administration of ribosomal RNA (rRNA) was found to protect mice against subsequent lethal infection by encephalomyocarditis (EMC) virus without induction of detectable amounts of circulating interferon. The nature of this effect was examined in terms of the types of natural polyribonucleotides which could afford such protection. rRNA prepared from E. coli was slightly more effective than chicken liver rRNA which was, in turn, more effective than yeast rRNA. 5S ribosomal RNA was not effective, whereas the slightly smaller 4S transfer RNA was as good as E. coli rRNA, suggesting that molecular size is not the sole criterion for the protective effect. The separated 16S and 23S E. coli rRNAs where each as effective as the unfractionated RNA. Anti-viral activity was lost after complete hydrolysis with alkali and nucleoside monophosphates were also inactive. Digestion of rRNA with pancreatic ribonuclease greatly decreased its antiviral activity whereas digestion with T1 ribonuclease had no effect indicating that fairly short oligonucleotides, but not of random nucleotide sequence, are active components in the protection of mice against infection by EMC virus. In vitro, no antiviral effect against EMC virus infection was observed in treatment of L cells under various conditions.

Functions of tRNAs and aminoacyl-tRNA synthetases not related to ribosomal protein synthesis

“…Третий класс акцепторных молекул представ ляет собой N-ацетилмурамилпепдид, являющийся промежуточным продуктом в синтезе межпептид ных мостиков стенки бактериальных клеток [12], Реакции переноса аминокислот на мурамилпептид инициируются аминоацилированием є-аминогруп пы остатков лизина одной пептидной цепи с после дующим удлинением вследствие ферментативного аминоацилирования первичной а-аминогруппы до завершения образования пептидной связи с остат ком D-аланина другой пептидной цепи в сложной молекуле пептидогликана. Известно, что другие тРНК также вовлекаются в синтез стенок бакте рий, например, стафилококковая тРНК с,[у , однако механизм этого процесса неясен [13].…”