Macromolecular Complexes of Aminoacyl-tRNA Synthetases from Eukaryotes. 2. Agarose Gel-Filtration Behaviour of the Extensively Purified High-Molecular-Weight Complex(es) of Seven Aminoacyl-tRNA Synthetases from Sheep Liver

1. Native DNA from two strains of Bacillus subtilis was chromatographed by stepwise elution from MAK (methylated albumin on kieselguhr). 2. Transforming activity was confined to two out of the three main fractions, activity being distributed between the two peaks differently for DNA from the different strains. 3. Fractionation of DNA from both strains on 2% agarose gel gave two components. Approx. 75% of the material was eluted within the void volume of the column. Approx. 25% of the material consisted of degradation products of lower molecular weight. 4. Chromatography on MAK of the material of high molecular weight eluted from agarose gel gave a number of peaks differing in molecular weight, indicating that degradation of the DNA takes place during chromatography on MAK. 5. The distribution of transforming activity among the fractions from MAK suggests that degradation occurs preferentially in certain regions of the DNA.

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Characterization Of Soluble DES-A And DES-AB Fibrin In Human Plasma At 37°C By Agarose-Gel Filtration

10.1055/s-0038-1653060 ◽

1981 ◽

Author(s):

G Müller-Berghaus ◽

J-C Bernhard ◽

I Mahn

Keyword(s):

Molecular Weight ◽

Human Plasma ◽

High Molecular Weight ◽

Gel Filtration ◽

Void Volume ◽

Agarose Gel ◽

High Molecular Weight Material ◽

Different Temperatures ◽

Lower Temperature

In two consecutive steps, thrombin cleaves the fibrinopeptides A and B from fibrinogen producing des-A fibrin and des-AB fibrin. Labeled des-A fibrin was prepared by batroxobin and labeled des-AB fibrin by clotting of 125I-fibrinogen with thrombin. Fibrin solubilized in buffered urea was mixed with plasma containing 131I-fibrinogen (fibrin:fibrinogen ratio = 1:20). These fibrinfibrinogen mixtures were applied to sepharose CL- 6B columns eq ui librated with buffered plasma (0.0025 M EDTA, 0.1 M NaCl, 0.05 M tris, 0.005 M EACA, 2 AT U hirudin/ml, 500 KIU a protinin/ml, 0.003 M NaN3, pH 7.4). Plasma was used as an equilibration and elution medium to prevent precipitation of fibrin in the columns. At 20°C, labeled des-A fibrin as well as des-AB fibrin were eluted in the void volume as high-molecular weight aggregates (peak A) and separated from m onomeric labeled fibrinogen (peak B). At 37°C, however, des- A fibrin was eluted at the same position as monomeric fibrinogen (peak B), whereas des-AB fibrin was eluted in the void volume as at 20°C. Rechromatography of isolated fractions of peak A and peak B at different temperatures showed that monomeric fibrin isolated at 37°C formed high molecular weight material at 20°C, and high-molecular weight fibrin isolated at 20°C dissociated at 37 ° C. The results suggest that des-A fibrin solubilized in plasma in the absence of calcium ismonomeric at 37°C but forms high-molecular weight aggregates at lower temperature, whereas des-AB fibrin is oligomeric at 20°C as well as at 37°C.

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