scholarly journals Cytochrome and intracellular oxidase

1930 ◽  
Vol 106 (746) ◽  
pp. 418-444 ◽  
Keyword(s):  
Molecular Oxygen ◽  
Heart Muscle ◽  
Organic Molecules ◽  
Functional Relationship ◽  
Living Cells ◽  
Yeast Cells ◽  
Respiratory Enzymes ◽  
Component C ◽  
Respiratory Mechanism ◽  
Three Components

It was shown previously that intracellullar hæmatin compounds such as cytochrome or free hæmatin are very widely if not universally distributed in aerobic organisms and that the oxidation and reduction of cytochrome can be easily observed in intact living cells. It was also shown that in living cells oxidised cytochrome is reduced by organic molecules or metabolites activated by dehydrogenases, while the reduced cytochrome is rapidly oxidised by indophenol oxidase. Cytochrome acts in this case as a carrier between two kinds of respiratory enzymes of the cell: oxidases and dehydrogenases. This type of the respiratory mechanism of the cell is therefore composed of (1) dehydrogenases; (2) the organic molecules or metabolites; (3) the three components of cytochrome and the unbound haematin; (4) the indophenol oxidase; and (5) the molecular oxygen. The main object of this paper is a more detailed study of the functional relationship between the two components of this system: oxidase and cytochrome. For this purpose it was found important to reconstruct the oxidase-cytochrome portion of the system from its two components obtained separately from cells or tissues. Unfortunately the attempts to obtain an active oxidase preparation completely free from cytochrome have failed, and it was found impossible to extract all the three components of cytochrome from cells containing them. A great deal of information concerning the oxidase-cytochrome system can be obtained, however, by comparing the activity of the heart muscle oxidase preparation with the somewhat reduced concentration of cytochrome, with the activity of the same preparation to which is added a certain amount of component c of cytochrome extracted from yeast cells.

scholarly journals Cytochrome and respiratory enzymes

1929 ◽  
Vol 104 (730) ◽  
pp. 206-252 ◽  
Keyword(s):  
Polyphenol Oxidase ◽  
Respiratory System ◽  
Living Cell ◽  
Functional Relationship ◽  
Muscle Cells ◽  
Respiratory Enzymes ◽  
Respiratory Mechanism ◽  
The Relationship

The object of this paper is the study of the functional relationship between the intracellular hæmatin compounds and the oxidising enzymes such as dehydrases and oxidases. It was shown previously (1925-1927) that aerobic organisms contain a very widely distributed intracellular hæmatin pigment-cytochrome-which can undergo reversible oxidation and reduction without being destroyed. Being the only compound directly visible in the living cell, cytochrome gives us important indications, not only of its own activity but also of that of other components of the respiratory system of the cell. The present paper will first deal with the thermostable peroxidase of yeast and other cells, and with the true thermostable oxidases such as the indophenol oxidase of yeast and muscle cells and the polyphenol oxidase of potato. This will be followed by the study of intracellular hæmatin compounds, and especially of the effects of various factors on the oxidation and reduction of cytochrome. The results of this study will enable us to determine the nature of the relationship between the oxidising enzymes and the intracellular hæmatin compounds, and this will help to elucidate at least one portion of the complicated respiratory mechanism, of the cell.

scholarly journals The porphyrin of component c of cytochrome and its relationship to other porphyrins

1930 ◽  
Vol 107 (751) ◽  
pp. 286-292 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Absorption Spectrum ◽  
Living Cells ◽  
Yeast Cells ◽  
Iron Porphyrin ◽  
Cell Component ◽  
Absorption Bands ◽  
Component C

Of the hæmatin compounds present in the cell, component c of cytochrome alone can be readily obtained in solution by extraction with water of either dry or acetone yeast (Keilin, 1925). Recently a method for extracting and concentrating this pigment from yeast has been described, and it was found that the component c thus obtained has the same properties as it has in intact living cells or in the extracts of dry of acetone yeast cells (Keilin, 1930, pp. 421-423). It was shown previously that cytochrome c is a hæmochromogen which differs from the usual hæmochromogen compounds in two important properties, namely, in not being autoxidisable and in not forming a carbon monoxide compound. It was also shown that, without changing it absorption spectrum, the component c can be easily modified in such a way as to show the properties of an ordinary hæmochromogen (Keilin, 1925, 1926). As the various hæmochromogens obtained from cytochrome c have the positions of the absorption bands very different from those of protohæmochromogens it was clear that the iron-porphyrin portion of its molecule is completely different from the ordinary protohæmatin. A series of facts discussed in previous papers suggested, however, that cytochrome originated from the ordinary protohæmatin which is also present in all cells of aerobic organisms. The object of the experiments described in this paper is the study of the porphyrin portion of cytochrome c and its relationship to other prophyrins, especially to protoporphyrin.

scholarly journals SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II

1932 ◽  
Vol 16 (2) ◽  
pp. 233-242 ◽  
Author(s):  
B. G. Wilkes ◽  
Elizabeth T. Palmer
Keyword(s):  
Physiological Activity ◽  
Outer Region ◽  
Living Cells ◽  
Yeast Cells ◽  
Live Cells ◽  
Intracellular Enzyme ◽  
Relationship Of ◽  
Kinetics Of

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H+) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen's α-glucosidase (maltase), was found.

Sporopollenin microcapsules for microencapsulation of living cells

2013 ◽  
Vol 1499 ◽  
Author(s):  
Shwan A. Hamad ◽  
Amro K.F. Dyab ◽  
Simeon D. Stoyanov ◽  
Vesselin N. Paunov
Keyword(s):  
Biological Activity ◽  
Mechanical Stress ◽  
Surface Active Agent ◽  
Aqueous Suspension ◽  
Active Agent ◽  
Living Cells ◽  
Yeast Cells ◽  
Original State ◽  
Lycopodium Clavatum ◽  
Surface Active

ABSTRACTWe used sporopollenin prepared from Lycopodium Clavatum to encapsulate living yeast cells as a model for probiotics. The microencapsulation of cells was achieved by using the trilite scars of the sporopollenin microcapsules which can open up by compressing the sporopollenin into a pellet. Such compressed pellets were exposed to an aqueous suspension of yeast cells in the presence of a biocompatible surface active agent which allowed living cells to be loaded inside the sporopollenin particles by the influx of liquid to the sporopollenin interior as the deformed microcapsules re-inflated to their original state. We demonstrated that the cells viability and biological activity is preserved after the microencapsulation in the sporopollenin. Such microencapsulation technology could find application in preserving cells from mechanical stress and aggressive environments which can be used in protection of probiotics in food formulations.

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