John C. Smith

The complete amino acid sequence of human fibroblast interferon as deduced using synthetic oligodeoxyribonucleotide primers of reverse transcriptase

Using synthetic oligodeoxyribonucleotides to prime the transcription of interferon mRNA and cDNA, we recently determined the mRNA sequence coding for the 47 amino-terminal amino acids of mature human fibroblast interferon (1). From this sequence, we have now synthesised an oligodeoxyribonucleotide that is homologous with the mRNA sequence coding for amino acids 42-45 and used it as a primer to selectively transcribe an interferon cDNA template. The sequence of the newly synthesised DNA predicted the sequence of amino acids 48-109 in the interferon polypeptide. By repeating this process with one more primer, we have determined the complete amino acid sequence of mature human fibroblast interferon, a polypeptide of 166 amino acids.

Inhibition of influenza virion transcriptases by polynucleotides

Abstract Poly(A), poly(I), poly(U), and a thiolated derivative poly(4-thiouridylic acid) inhibit the virion-associated transcriptase of influenza A/Victoria/75 with IDS 50 values of 300, 40, 4, and 1 μg/ml, respectively. A copolymer containing 9% cytidine and 91% 4-thiouridine residues (poly(C,S 4 U 10 )) inhibits the transcriptase to the same extent as poly(4-thiouridylic acid) and the copolymer also inhibits the transcriptase from a range of A strain influenzas, B/Lee/40 and fowl plague virus. Inhibition by poly(U) is dependent on the polymeric nature of the compound: inhibition decreases with oligomers of 20 residues and less. A sugar-phosphate backbone appears to be important for inhibition since vinyl analogs of poly(U) and poly(A) have little or no inhibitory activity.