Bovine proinsulin has been crystallized under a variety of conditions at both neutral and acid pH. Microtechniques were employed with sample weights of about 200 mug and volumes of 5-20 mul. The crystalline preparations all differ from each other morphologically.X-ray photographs of one form, tetragonal bipyramids grown at pH 3 with added ammonium sulphate solution, established the space group P4(1)2(1)2 (or its enantiomorph P4(3)2(1)2). The cell dimensions are a = 50.8 +/- 0.2 A, c = 148.0 +/- 0.4 A. The asymmetric unit in this form is a dimer of proinsulin which is also the dominant species in solution at this pH.

Animals↗

PubMed1968

Diffusible thromboplastins of human cancer and chorion tissue.

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Chromatography↗

PubMed1967

Antithromboplastic and thromboplastic activities of fatty acids.

In the course of systematic research into the coagulative properties of cancers, facts of wider implication on the behaviour of fatty acids in relation to clotting have been uncovered. It has been shown that saturated fatty acids of appropriate chain length have a direct inhibitory effect on tissue thromboplastins with an optimum of 14 carbon atoms. Unsaturated fatty acids have a similar, though more marked, inhibitory activity with an optimum chain length of 16 carbon atoms. The inhibitory activity is reduced by combining the acids with human serum albumin. Certain fatty acids when dissolved in human serum albumin form labile thromboplastins with properties corresponding to those found in human cancers and in chorion.

Anticoagulants↗