The purification of human caeruloplasmin

Abstract

SYNTHESIS OF PROTEIN AND RIBONUCLEIC ACID 279 results do not, however, exclude the possibility that there might be coupling between the synthesis of certain proteins and the synthesis of some particular fraction of the ribonucleic acid. Whether protein synthesis can be suppressed without affecting RNA synthesis remains undecided, since the amino acid analogue, somewhat paradoxically, inhibited RNA synthesis much more readily than protein synthesis. Both thienylalanine and azaguanine suppressed cytoplasmic RNA synthesis more rapidly than nuclear RNA synthesis, thus indicating that there is no rigid coupling between these two processes either. No dissociation of nuclear from cytoplasmic protein synthesis was observed: thienylalanine produced no change in the rate of either nuclear or cytoplasmic synthesis over 12 hr., and azaguanine reduced the rate of synthesis in nucleus and cytoplasm to about the same extent. SUMMARY 1. Radioautographic methods were used to study the effect of B-2-thienylalanine and 8azaguanine on the synthesis of protein and ribonucleic acid in the nucleus and cytoplasm of the rat connective-tissue cell. 2. With ,-2-thienylalanine it was possible to reduce the rate of ribonucleic acid synthesis in the cytoplasm to about 10 % of the normal value, and in the nucleus to about 50 % of the normal value, without affecting either nuclear or cytoplasmic protein synthesis. 3. With both ,-2-thienylalanine and 8-azaguanine, cytoplasmic ribonucleic acid synthesis was much more rapidly suppressed than nuclear ribonucleic acid synthesis. 4. The results indicate that there is no mandatory coupling between the synthesis of ribonucleic acid and the synthesis of protein, as measured by the overall rates of the two processes, either in the nucleus or in the cytoplasm. This work was supported by a personal grant from the British Empire Cancer Campaign. It is a pleasure to thank Miss Marianne Jahnz for her careful technical assistance.

The inhibition of caeruloplasmin by azide

“…A preliminary report on part of this work has appeared (Curzon, 1965a Broman et al (1963) and Morell, 1957;Curzon & Vallet, 1960;Deutsch, Kasper & Walsh, 1962 NN-Dimethyl-p-phenylenediamine sulphate. This compound was obtained from Kodak Ltd. and purified by dissolving it in methanol containing a little 5% SO2, removing the insoluble residue byffltration and precipitating the compound with ether.…”

İçme Sularında Yüksek Nitrat Bulunan Akkaraman Koyunlarda Serum Seruloplazmin, Paraoksanaz ve Nitrik Oksit Düzeyleri

“…pH 5.2 ve 37°C koşullarında asetat tamponunda hazırlanan P-fenilen diamin diklorid (PPD) serum örnekleri ile oluşan renkli ürünün absorbansı spektrometrede 550 nm'de okunarak serum seruloplazmin ölçümleri incelendi [14] .…”

A Comparative Study of Hydroxyindole Oxidases

“…It was also rapidly oxidized by the gill plate enzyme, at about the same rate as 5-hydroxytryptamine. It is known that 5-hydroxyindoleacetic acid is oxidized by human caeruloplasmin (Curzon and Vallet, 1960).…”

“…Erspamer (1955) has shown that in man and dog less than one-half of the amine administered is excreted as 5-hydroxyindoleacetic acid in the urine, and he has found that in a number of herbivorous species the urine contains only insignificant amounts of 5-hydroxyindoleacetic acid. It is not known to what extent this deficit is accounted for by known metabolites of 5-hydroxytryptamine, for example, the 0-glucuronate and the O-sulphate, the N-acetyl derivative or 5-hydroxyindoleaceturic acid (Curzon, 1957;Chadwick and Wilkinson, 1958;McIsaac and Page, 1959).…”

“…Caeruloplasmin, the copper containing protein of mammalian plasma, has been reported to act on 5-hydroxytryptamine (Porter, Titus, Sanders and Smith, 1957;Martin, Eriksen and Benditt, 1958;Nakajima and Thuillier, 1958;Siva Sankar, 1959;Zarafonetis and Kalas, 1960;Curzon and Vallet, 1960). Since caeruloplasmin is also able to oxidize catechol compounds and, as a copper enzyme, is cyanide-sensitive, it was decided to compare the action of the oxidase from Mytilus gill plates with that of pig plasma caeruloplasmin.…”