Chymotrypsinogen synthesis in the exocrine cell of the guinea pig pancreas was studied under the following conditions: Animals fed after a fast of ∼48 hours received ∼1 hour after feeding an intravenous injection of DL-leucine-1-C14. At various time intervals (1 to 45 minutes) after the injection, the glands were removed and fractionated into a series of cell fractions of known cytological significance. Ten to twelve animals were used for each time point. From each cell fraction, the chymotrypsinogen was isolated by acid extraction and purified by (NH4)2SO4 fractionation, isoelectric precipitation, and chromatography. Because of the minuteness of the quantities involved, chymotrypsinogen amounts were calculated from enzymatic activity figures, and a carrier method was used to precipitate and count the enzyme. The chymotrypsinogen isolated from the attached ribonucleoprotein particles of the microsomal fraction had the highest specific radioactivity at the early time points (1 to 3 minutes). After long intervals (at 15 to 45 minutes), the specific radioactivity of the enzyme increased in the microsomal contents and finally in the zymogen granules. The results are compatible with the view that the chymotrypsinogen is synthesized in or on the attached RNP particles and subsequently transported to other cell compartments.
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1 July 1960
Content prior to 1962 was published under the journal name
The Journal of Biophysical and Biochemical Cytology
Article|
July 01 1960
A Cytochemical Study on the Pancreas of the Guinea Pig : V. In vivo Incorporation of Leucine-1-C14 into the Chymotrypsinogen of Various Cell Fractions
Philip Siekevitz,
Philip Siekevitz
From The Rockefeller Institute
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George E. Palade
George E. Palade
From The Rockefeller Institute
Search for other works by this author on:
Philip Siekevitz
From The Rockefeller Institute
George E. Palade
From The Rockefeller Institute
Received:
November 15 1959
Copyright, 1960, by The Rockefeller Institute Press
1960
J Biophys and Biochem Cytol (1960) 7 (4): 619–630.
Article history
Received:
November 15 1959
Citation
Philip Siekevitz, George E. Palade; A Cytochemical Study on the Pancreas of the Guinea Pig : V. In vivo Incorporation of Leucine-1-C14 into the Chymotrypsinogen of Various Cell Fractions . J Biophys and Biochem Cytol 1 July 1960; 7 (4): 619–630. doi: https://doi.org/10.1083/jcb.7.4.619
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