Über den Abbau der Thymo‐nucleinsäure durch Pankreasferment, (Nucleinsäuren, I)

The Chemistry of the Nucleic Acids and Nucleoproteins

“…The a-nucleic acid of thymus, the large polynucleotide of which the soluble salts show gel-forming properties, is converted by the nucleogelase of commercial pancreatin into the o-acid which no longer forms gels but is still precipitable by acids from solutions of its salts (120,121). On the other hand, laboratory-made extracts of fresh or dried pancreas contain an enzyme, thymopolynucleotidase, which causes a more fundamental hydrolysis of the a-acid, either previously isolated or while still present in the minced thymus gland (128,129,130) ; presumably it attacks the P-acid similarly. An enzyme causing similar effects has been recorded as present in a variety of animal and plant tissues and named thymonucleodepolymerase ( 13 1, 132).…”

“…The results of thymopolynucleotidase action were a fall in viscosity and rise in conductivity of the solution and the liberation of one acid equivalent (titrated to pH 9) for each four atoms of phosphorus present ; the products were oligonucleotides corresponding to 3.9 nucleotides in size (129,130). Oligonucleotides are amorphous powders and differ from the a-and pacids in being soluble in hydrochloric acid and in having sodium and magnesium salts which dissolve in their own weight of water to form solutions which are viscous but do not gel.…”

“…It has been postulated (113,129,133) that the oligonucleotides (I) are true "structural tetranucleotides" from which the polynucleotides are formed by polymerisation and that the tetranucleotide has the structure given to it by Levene (135). Definite positions were assigned (113) to the nucleotides of adenine and thymine, the relative orientation of the others being undetermined, on the basis of the following experiments.…”

Factors influencing the nucleoprotein content of fibroblasts growing in vitro

“…Both types of nucleic acid are hydrolysed by plasma to compounds no longer precipitable by the uranyl acetate reagent (Table 2), but the ribonucleic acid suffers more decomposition than the thymonucleic acid. Cockerel plasma therefore contains enzymes of the nuclease type such as ribonuclease [Kunitz, 1940], and thymonucleodepolymerase [Fischer, Bottger & Lehmann-Echternacht, 1941;Greenstein & Jenrette, 1941], as well as nucleotidases, phosphatases, etc. Table 2.…”

Über die Thymo-polynucleotidase aus Pankreas. Nucleinsäuren. V

“…Bei pn = 5 bzw. 7 werden sie etwas schneller inaktiv, sehr schnell bei stärkeren Alkalitäten (8,2). Geprüft wurden ein 2 mal mit Ammonsulfat fraktioniert umgefälltes Präparat aus getrocknetem Schweinepankreas und ein solches aus frischem Kinderpankreas, die in m/15-Phosphatlösungen des entsprechenden pn 6,5 Stunden bei 20° gestanden waren und dann, nach Einstellung gleicher Acidität mit Boratpuffer, auf Mg-nucleinat einwirkten.…”