Slime molds discoideum

These studies demonstrate the general mechanism of synchronization of biochemical systems, which I expect to be operative in even more complex systems, such as the mitochondrial respiration or the periodic activity of the slime mold Dictyostelium discoideum. As shown in a number of laboratories under suitable conditions mitochondrial respiration can break into self-sustained oscillations of ATP and ADP, NADH, cytochromes, and oxygen uptake as well as various ion transport and proton transport functions. It is important to note that mitochondrial respiration and oxidative phosphorylation under conditions of oscillations is open for the source, namely, oxygen, as well as with respect to a number of sink reactions producing water, carbon dioxide, and heat. 

As described in Box 11-C, the ameboid cells of the slime mold Dictyostelium discoideum are attracted to nutrients such as folic acid during their growth stage. Later, as the cells undergo developmental changes they become attracted by pulses of cyclic AMP.330 Occupancy of 7-helix receptors for cAMP on the outer plasma membrane appears to induce methylation of both proteins and phospholipids and a rise in cytosolic Ca2+ and changes in the cytoskeleton that result in preferential extension of the actin-rich pseudopods toward the chemoattractant.331... 

Isolation of a 2-acetamido-2-deoxy-D-galactose-binding protein from a slime mold, Dictyostelium discoideum, was reported by Rosen and coworkers.779,780 Affinity chromatography on Sepharose 4B, followed by... 

Dictyostelium discoideum is a cellular slime mold, an amoeba. It is a preferred object for the study of cell locomotion, chemotaxis and differentiation. 

The most important compounds from this class are undoubtedly 3,6-anhydrofuranoses. Fura-nodictine A and B (produced by cellular slime mold Dictyostelium discoideum) showing neuronal differentiation activity [54] are good examples. These interesting derivatives may be conveniently obtained from the open-chain sugars. For example, synthesis of furanodictine A was realized from compound 85 obtained from D-arabinose in a few well-defined steps as shown inO Fig. 19 [55]. 

Enzymatic deamination of the naturally occurring pteridin-6-yl acyclo C-nucleosides biopterin (615), dictypterin (616), o-neopterin (618), and d-monapterin (620) with pterin deaminase from the slime mold Dictyostelium discoideum caused their conversion to the corresponding lumazin-6-yl 2,4-dioxopyrazino[2,3-d]pyrimidin-6-yl acyclo C-nucleosides biolumazine (672), dictyolumazine (673), D-neolumazine (674), and D-monalumazine (675), respectively (94MI2) (Scheme 174). 

Orellanine (0.4 mM) inhibited photosynthesis in Lemna minor,without affecting the chloroplast electron transport chain [107], It inhibited growth of Escherichia coli and the slime mold Dictyostelium discoideum [108]. Orellanine (and orelline 17) suppressed the toxicity of aluminum ions on the fungus Mycena seplenlrionalis, via formation of a 16(or 17J-A1+3 complex [109]. The phototransformation of 16 to 17 has been described [110]. 

Distribution and properties of GDH s in over 40 species of fungi have been reviewed by LeJohn (23) who has concluded that, whereas higher fungi of the classes Deuteromycetes, Ascomycetes, and Basidiomycetes possess two distinct enzymes, lower fungi, members of the Phycomycetes and Myxomycetes (slime molds), have only one enzyme active with NAD. However, vegetative cell homogenates of Dictyostelium discoideum possess both an enzyme that is active with NAD and NADP, and one active only with NAD 2Ji). 

Bonner, J.T. 1947. Evidence for the formation of cell aggregates by chemotaxis in the development of the slime mold Dictyostelium discoideum. J. Exp. Zool. 106 1-26. 

Goldbeter, A. J.L. Martiel. 1985. Birh5dhmicity in a model for the cyclic AMP signaling system of the slime mold Dictyostelium discoideum. FEBS Lett. 191 149-53. 

Raper, K.B. 1935. Dictyostelium discoideum, a new species of slime mold from decaying forest leaves. J. Agricult. Res. 50 135-47. 

CjHiiNsOj, Mr 237.22. The (l J ,2 S) form (L-erythro form) form ale yellow cryst., mp. 250-280 C (decomp.), [a]o-66 (0.1 m HCI), pK, 2.23, pK 2 7.89. In alkaline solution B. shows blue fluorescence. It is widely distributed in microorganisms, insects (e.g. in royaI jelly of queen bees), algae, amphibians, and mammals and is also found in urine. In metabolism tet-rahydro-B. acts as a cofactor for phenylalanine 4-monooxygenase (EC 1.14.16.1). B. is a growth factor for insects. The (l /, 2 /f) form (D-threo form) known as dictyopterin melts at >300 C and has pK , 2.20, pKa2 7.92. It occurs in the slime mold Dictyostelium discoideum. The biosynthesis starts from guanosine triphosphate. 

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