Use of liquid nitrogen and high ionic strength for the isolation of functional polyribosomes from Neurospora crassa

Expression of domains of mouse alpha-fetoprotein in Escherichia coli

A mouse alpha-fetoprotein complementary DNA containing the coding region for amino acids 256 to 548 was fused to the lac transcriptional and translational control elements contained on the expression vector pOP203-28. The expression of a 35 kD hybrid lac Z'- alpha-fetoprotein polypeptide in Escherichia coli was demonstrated by the chloramphenicol release assay and by immunoprecipitation using rabbit anti-mouse alpha-fetoprotein antibodies as probe.

New class of ribonucleic acid in Neurospora associated with the outer cell envelope

Extrinsic ribonucleic acid (RNA) can be isolated from a KCl extract of Neurospora crassa conidial cell surface products. It is heterogeneous in size. The bulk of this RNA travels as a broad band, trailing the 5.8S ribosomal marker RNA on electrophoretic gels. The extrinsic RNA, when denatured, exhibites several discrete lengths between 50,000 and 130,000 daltons. Melting profiles confirm the heterogeneity of the RNA and indicate that 58% of the bases are involved in hydrogen bonding. Analyses of alkaline hydrolysis products reveal no extensive methylation and few or none of the unusual bases present in transfer RNA. The bases are present in approximately equivalent amounts. Extrinsic RNA represents 2 to 3% of the total cellular RNA. Since this membrane-associated class of RNA does not resemble ribosomal RNA, messenger RNA, or transfer RNA and since it is extracted from the cell exterior by methods used to remove extrinsic membrane molecules, we have designated it extrinsic RNA.