scholarly journals Kleptoprotein bioluminescence: Parapriacanthus fish obtain luciferase from ostracod prey

2020 ◽  
Vol 6 (2) ◽  
pp. eaax4942 ◽  
Author(s):  
Manabu Bessho-Uehara ◽  
Naoyuki Yamamoto ◽  
Shuji Shigenobu ◽  
Hitoshi Mori ◽  
Keiko Kuwata ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Small Molecules ◽  
Monarch Butterflies ◽  
Light Organs ◽  
Specific Uptake ◽  
Luciferase Enzyme

Through their diet, animals can obtain substances essential for imparting special characteristics, such as toxins in monarch butterflies and luminescent substances in jellyfishes. These substances are typically small molecules because they are less likely to be digested and may be hard for the consumer to biosynthesize. Here, we report that Parapriacanthus ransonneti, a bioluminescent fish, obtains not only its luciferin but also its luciferase enzyme from bioluminescent ostracod prey. The enzyme purified from the fish’s light organs was identical to the luciferase of Cypridina noctiluca, a bioluminescent ostracod that they feed upon. Experiments where fish were fed with a related ostracod, Vargula hilgendorfii, demonstrated the specific uptake of the luciferase to the fish’s light organs. This “kleptoprotein” system allows an organism to use novel functional proteins that are not encoded in its genome and provides an evolutionary alternative to DNA-based molecular evolution.

Molecular evolution pathways during nucleation of small organic molecules: solute-rich pre-nucleation species enable control over the nucleation process

2020 ◽  
Vol 22 (33) ◽  
pp. 18663-18671
Author(s):  
Shuyi Zong ◽  
Jingkang Wang ◽  
Xin Huang ◽  
Ting Wang ◽  
Qi Liu ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Small Molecules ◽  
Organic Molecules ◽  
Nucleation Process ◽  
Small Organic Molecules

The pre-nucleation clusters played a key role in the process of crystallization of organic small molecules, indicating that the dynamics of nucleation could be regulated by changing the structure and size of the pre-nucleation clusters.

scholarly journals Inactivation of Octopamine in Larval Firefly Light Organs by a High-Affinity Uptake Mechanism

1986 ◽  
Vol 122 (1) ◽  
pp. 369-385
Author(s):  
ALBERT D. CARLSON ◽  
PETER D. EVANS
Keyword(s):  
Potent Inhibitor ◽  
Nerve Terminals ◽  
Uptake System ◽  
Uptake Mechanism ◽  
High Affinity ◽  
High Affinity Uptake ◽  
Light Organs ◽  
Specific Uptake ◽  
Uptake Studies ◽  
Firefly Light

1. Uptake studies using radioactive octopamine have revealed that the larval lantern of the Photuris firefly possesses a concentrative, high-affinity uptake system for octopamine. This compound has been shown previously to be the neurotransmitter of the photomotor neurones. 2. Imipramine is a potent inhibitor of the uptake of octopamine in the lantern. At 10−1moll−4 it reduces specific uptake of radioactive octopamine with a Ki of 5.8 × 1O−1moll−1. Incubation of lanterns in 2.5 × 1O−4moll−1 imipramine induces an increase in sensitivity of the luminescent response to endogenously released and exogenously applied octopamine. Release of endogenous octopamine is potentiated in imipramine-treated lanterns, which also show a significant reduction of octopamine content with this treatment 3. Uptake of octopamine does not appear to be affected by denervation of the lanterns, suggesting that nerve terminals are not the principal sites of octopamine uptake.

scholarly journals The Spectral Distribution of Firefly Light. II

1967 ◽  
Vol 50 (6) ◽  
pp. 1681-1692 ◽  
Author(s):  
W. H. Biggley ◽  
J. E. Lloyd ◽  
H. H. Seliger
Keyword(s):  
Spectrophotometric Study ◽  
Single Individual ◽  
Spectral Measurements ◽  
Statistical Precision ◽  
Light Organs ◽  
Distinct Color ◽  
Luciferase Enzyme ◽  
Special Case ◽  
Peak Emission

The in vivo peak emission wavelengths of bioluminescence are reported for 15 species of American fireflies. A spectrophotometric study of the dorsal light organs of 155 specimens of the Jamaican firefly Pyrophorus plagiophthalamus showed three distinct color distributions with peak emission wavelengths at 550.1 ± 1.5 mµ, 556.8 ± 1.4 mµ, and 562.4 ± 1.0 mµ. Similar spectral measurements of 35 ventral light organs of the same insects gave peak emission wavelengths ranging from 547 through 594 mµ. This is a wider distribution than the total range of all 34 species of firefly studied to date. There was no obvious correlation between the colors of the ventral and dorsal light organs. It appears that P. plagiophthalamus is a special case in which the luciferase enzyme is not only different among members of the same species, but it may be different for the dorsal and ventral light organs in a single individual. A minimum of six different luciferase molecules for P. plagiophthalamus ventral light organs is proposed. The statistical precision in making these spectrophotometric measurements is discussed.

Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

1992 ◽  
Vol 50 (1) ◽  
pp. 706-707
Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert
Keyword(s):  
Gap Junctions ◽  
Small Molecules ◽  
Manduca Sexta ◽  
Freeze Fracture ◽  
Cell Communication ◽  
Cellular Level ◽  
Thin Sections ◽  
Prothoracic Glands ◽  
Polyhydroxylated Steroids ◽  
Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

Immunocytochemistry after fast freeze fixation-freeze substitution: Advantages and limits

1990 ◽  
Vol 48 (3) ◽  
pp. 42-43
Author(s):  
Marie-Thérèse Nicolas
Keyword(s):  
Osmium Tetroxide ◽  
Freeze Substitution ◽  
Acrylic Resin ◽  
Expected Improvement ◽  
List Type ◽  
Chemical Fixation ◽  
Freeze Fixation ◽  
Liquid Chemical ◽  
Luciferase Enzyme ◽  
Lower Background

An alternative to aqueous chemical fixation consists in immobilizing physically the specimen by freezing it as fast as possible without using any cryoprotectant. This Fast Freeze Fixation (FFF) followed by Freeze Substitution (FS) avoids osmotic artefacts due to the slow penetration of liquid chemical fixative. Associated with Immuno-Gold labeling (IGS), FFF-FS allows a more precise localization of antigens.Using the bioluminescent bacteria Vibrio harveyi, a comparison of IGS with an antibody directed against its luciferase (enzyme of the luminescent reaction) has been done after liquid chemical fixation versus FFFFS. This later technique, beside an expected improvement of the ultrastructure always shows a better preservation of antigenicity and a lower background. In the case of FFF-FS technique (Figure 3):–labeling in acrylic resin (LRWhite) is 2 to 4 fold more intense than in epoxy resin (Epon),–but the ultrastructure is always better in Epon.–but the ultrastructure is always better in Epon.–The addition of fixatives in the substitution medium, results in a decrease of labeling which is more important in the case of a mixture of fixatives than with osmium tetroxide alone; with one exception: the substitution with glutaraldehyde which produces a dramatic increase in the density of the labeling but also, at the same time, a swelling of the cells of about 30%.

Fusion and Fission Processes in Exocytosis: Possible Roles for Synexin and Osmotic Lysis in the Two Events

1980 ◽  
Vol 38 ◽  
pp. 594-597
Author(s):  
H.B. Pollard ◽  
C.E. Creutz ◽  
C.J. Pazoles ◽  
J.H. Scott
Keyword(s):  
Small Molecules ◽  
Chromaffin Cells ◽  
Adrenal Glands ◽  
General Concept ◽  
Extracellular Calcium ◽  
Large Protein ◽  
Granule Membrane ◽  
Osmotic Lysis ◽  
Per Se ◽  
Chemical Evidence

Exocytosis is a general concept describing secretion of enzymes, hormones and transmitters that are otherwise sequestered in intracellular granules. Chemical evidence for this concept was first gathered from studies on chromaffin cells in perfused adrenal glands, in which it was found that granule contents, including both large protein and small molecules such as adrenaline and ATP, were released together while the granule membrane was retained in the cell. A number of exhaustive reviews of this early work have been published and are summarized in Reference 1. The critical experiments demonstrating the importance of extracellular calcium for exocytosis per se were also first performed in this system (2,3), further indicating the substantial service given by chromaffin cells to those interested in secretory phenomena over the years.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

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