Protein chain initiation by methionyl-tRNA in wheat embryo.

The mechanism of protein chain initiation has been investigated in a cell-free amino acid incorporation system from wheat embryos dependent on tobacco mosaic virus RNA. Analysis of the N-termini of the labeled peptide products of short-term incubations showed the presence of unblocked methionine. In addition, methionyl-tRNA (Met-tRNA) could be bound to ribosomes at 1.

Aurintricarboxylic acid and initiation factors of wheat embryo.

In extracts of wheat embryo, aurintricarboxylic acid inhibits attachment of ribosomes to messenger RNA and has little effect on aminoacyl transfer to peptide. This specificity of inhibition allows (i) the demonstration that the initial phase of amino acid incorporation dependent on RNA of tobacco mosaic virus involves an "initiation" reaction between ribosome and messenger RNA which requires two soluble factors, (ii) an assay facilitating purification of the initiation factors, and (iii) the demonstration that these factors are distinct from aminoacyl transfer enzymes.

Polyribosome isolation in the presence of diethyl pyrocarbonate.

Isolation of polyribosomes from wheat embryos and corn root tips in the presence of diethyl pyrocarbonate showed this reagent to have a protective effect on polyribosome structure. In addition, the use of diethyl pyrocarbonate allowed initial homogenization to be performed under less stringent conditions than those normally employed for polyribosome isolation. The use of the reagent is however limited, in that it is deleterious to in vitro ribosomal amino acid incorporation.

Endrin food-poisoning. A report on four outbreaks caused by two separate shipments of endrin-contaminated flour.

Between 3 June and 15 July 1967 four explosive outbreaks of acute poisoning with the insecticide endrin occurred in Doha in Qatar and Hofuf in Saudi Arabia. Altogether 874 persons were hospitalized and 26 died. It is estimated that many others were poisoned whose symptoms were not so severe as to cause them to seek medical care or to enter hospital.