title: The use of cation-bound microsomes for studies of protein synthesis.
abstract: Low speed microsomes prepared by centrifuging at 30 times g for 10 minutes after interaction with Ca-2plus or Mg-2plus are comparable to high speed microsomes (105,000 times g) with respect to incorporation of 3-H-leucine in vivo, protein-synthesizing ability in vitro, and the pattern of ribosomal profiles on a linear sucrose density gradient. Low and high speed polyribosomes, i.e., those isolated with and without Ca-2plus or Mg-2plus from a postmitochondrial supernatant, also displayed similar protein-synthesizing capability in vitro and identical profiles on a linear sucrose density gradient. Other divalent cations, such as Ba-2plus, Ni-2plus, Co-2plus, Cu-2plus, Fe-2plus, Hg-2plus, Zn-2plus, and Sr-2plus, inhibited enzyme activities and depressed protein synthesis. Low speed microsomes may now be deemed suitable for all studies of microsomal function.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002251:Carbon Tetrachloride / Q000494:pharmacology; D002413:Cations, Divalent; D002499:Centrifugation, Density Gradient; D003513:Cycloheximide / Q000494:pharmacology; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000648:ultrastructure; D008274:Magnesium / Q000494:pharmacology; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D012270:Ribosomes / Q000378:metabolism; D013395:Sucrose
chemical_list: D002413:Cations, Divalent; D013395:Sucrose; D003513:Cycloheximide; D002251:Carbon Tetrachloride; D007930:Leucine; D008274:Magnesium; D002118:Calcium; D010634:Phenobarbital