Differences in the ribosomes prepared from lactating and non-lactating bovine mammary gland.
1. Ribosomes prepared from bovine lactating mammary gland are able to synthesize protein, whereas similar preparations from non-lactating glands are not. Washing the ribosome suspensions through a medium containing 0.5m-ammonium chloride enhanced their ability to incorporate phenylalanine into polyphenylalanine. 2. Ribosomes isolated from non-lactating bovine mammary gland, in contrast with those from rat liver and lactating mammary gland, contained significant amounts of extraneous nucleases. These enzymes could be removed by washing with a medium A buffer containing 0.5m-ammonium chloride. 3. Only those ribosomes from functionally active tissues were able to bind polyuridylic acid and phenylalanyl-tRNA.
D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002499:Centrifugation, Density Gradient; D005260:Female; D007774:Lactation; D008099:Liver / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism; D011247:Pregnancy; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000378:metabolism; D051381:Rats; D012260:Ribonucleases / Q000032:analysis; D012270:Ribosomes / Q000032:analysis / Q000378:metabolism*; D013395:Sucrose; D013997:Time Factors; D014316:Tritium; D014500:Uracil Nucleotides / Q000378:metabolism
D014500:Uracil Nucleotides; D000643:Ammonium Chloride; D014316:Tritium; D010649:Phenylalanine; D013395:Sucrose; D012343:RNA, Transfer; D012260:Ribonucleases