Volume 72, Issue 7-8 - The Special Section is dedicated to the memory of Professor Lothar Jaenicke / Editor: Wilhelm Boland

The biochemist Lothar Jaenicke died on 29 December 2015, aged 92 years old. The last time I saw him was at his 90 th birthday on 14 September 2013, at the occasion of which his colleagues at the Universität zu Köln (Cologne) in Germany had organized a symposium to honor him.

Among the post-war European biochemists, L. Jaenicke (1923–2015) stands out as a distinctive character with bright ideas and professional elegance, yet with personal modesty. His contributions to diverse fields such as C1 metabolic pathways, signal compounds (aquatic sex attractants) of brown algae and chemotaxis appear as distinctive features not covered by his peers. His rich scientific œuvre is documented in 291 journal articles, nine books, and a huge number of almost 570 book reviews, recensions, biographies and commentaries on the politics of science and the history of biochemistry. A quantitative approach is attempted here to make his diversified life’s work more transparent through graphical analysis by the novel method of ergography. At a glance, his different strands of activities stand out clearly and speak for themselves, without the need for excessive verbal interpretation.

The Arabidopsis thaliana R2R3-MYB transcription factor MYB12 is a light-inducible, flavonol-specific activator of flavonoid biosynthesis. The transactivation activity of the At MYB12 protein was analyzed using a C-terminal deletion series in a transient A. thaliana protoplast assay with the goal of mapping the activation domain (AD). Although the deletion of the last 46 C-terminal amino acids did not affect the activation capacity, the deletion of the last 98 amino acids almost totally abolished transactivation of two different target promoters. A domain swap experiment using the yeast GAL4 DNA-binding domain revealed that the region from positions 282 to 328 of At MYB12 was sufficient for transactivation. In contrast to the R2R3-MYB ADs known thus far, that of At MYB12 is not located at the rearmost C-terminal end of the protein. The At MYB12 AD is conserved in other experimentally proven R2R3-MYB flavonol regulators from different species.

A new isoquinoline quinone system and its iodinated derivatives were isolated from the ascidian tunicate Ascidia virginea Müller 1776 (Phlebobranchia: Ascidiidae). Structures were elucidated by spectroscopic methods and derivatization reactions. Ascidine A (3,7-dihydro-1,8-dihydroxy-4-(4′-hydroxyphenyl)isoquinoline-3,7-dione ( 1 ), ascidine B (3,7-dihydro-1,8-dihydroxy-4-(4′-hydroxy-3′-iodophenyl)isoquinoline-3,7-dione ( 2 ), and ascidine C (3,7-dihydro-1,8-dihydroxy-4-(4′-hydroxy-3′,5′-diiodophenyl)isoquinoline-3,7-dione ( 3 ) represent a novel type of tyrosine-derived alkaloids.

Abstract: Analysis by gas chromatography/mass spectrometry of the scent gland secretions of male and female Middle American burrowing pythons ( Loxocemus bicolor ) revealed the presence of over 300 components including cholesterol, fatty acids, glyceryl monoalkyl ethers, and alcohols. The fatty acids, over 100 of which were identified, constitute most of the compounds in the secretions and show the greatest structural diversity. They include saturated and unsaturated, unbranched and mono-, di-, and trimethyl-branched compounds ranging in carbon-chain length from 13 to 24. The glyceryl monoethers possess saturated or unsaturated, straight or methyl-branched alkyl chains ranging in carbon-chain length from 13 to 24. Alcohols, which have not previously been reported from the scent glands, possess straight, chiefly saturated carbon chains ranging in length from 13 to 24. Sex or individual differences in secretion composition were not observed. Compounds in the scent gland secretions of L. bicolor may deter offending arthropods, such as ants.

Abstract: Tricholoma populinum Lange is an edible basidiomycete from the family Tricholomataceae. Extracts, fractions, and different metabolites isolated from the fruiting bodies of this mushroom were tested for degranulation-inhibiting activities on RBL-2H3 cells (rat basophils). Dichloromethane extracts decreased degranulation significantly, as did a fraction after column chromatography. In addition, the extract decreased the IL-2 release from Jurkat T cells and the release of IL-8 from HMC-1 human mast cells. The results show the significant effects of extracts of T. populinum on cells of the innate (basophils and mast cells) and adaptive (T cells) immune system and indicate the influence of the mushroom on different immunological processes. As one fraction showed activity, it seems to be possible that it includes an active principle. The compounds responsible for this effect, however, could not be identified as the contents oleic acid ( 1 ), ergosterol peroxide ( 2 ), and 9,11-dehydroergosterol peroxide ( 3 ) showed no effects. Nevertheless, the mushroom could be used for supporting allergy treatment in future studies.

In higher plants, jasmonates are lipid-derived signaling molecules that control many physiological processes, including responses to abiotic stress, defenses against insects and pathogens, and development. Among jasmonates, ω-oxidized compounds form an important subfamily. The biological roles of these ω-modified derivatives are not fully understood, largely due to their limited availability. Herein, a brief (two-step), simple and efficient (>80% yield), versatile, gram-scalable, and environmentally friendly synthetic route to ω-oxidized jasmonates is described. The approach utilizes olefin cross-metathesis as the key step employing inexpensive, commercially available substrates and catalysts.

Hepatocellular carcinoma is a burgeoning health issue in sub-Saharan Africa and East Asia where it is most prevalent. The search for gene medicine treatment modalities for this condition represents a novel departure from current treatment options and is gaining momentum. Here we report on nonPEGylated and on sterically stabilized PEGylated cationic liposomes decorated with D-galacto moieties linked to 24.1 Å spacers for asialoglycoprotein receptor (ASGP-R)-targeted vehiculation of pCMV-luc plasmid DNA. Cargo DNA is fully liposome associated at N/P ratio=3:1 and is partially protected from the effects of serum nucleases. Moreover, at this ratio, lipoplex dimensions (89–97 nm) are compatible with the requirements for extravasation in vivo. Ethidium displacement assays show that the reporter DNA is in a less condensed state when bound to PEGylated liposomes than with nonPEGylated liposomes. PEGylated lipoplexes were well tolerated by both HEK293 (ASGP-R-negative) and HepG2 (ASGP-R-positive) cell lines and delivered DNA to the human hepatoma cell line HepG2 by ASGP-R mediation at levels three-fold greater than nonPEGylated lipoplexes. PEGylated ASGP-R-targeted liposomes reported in this study possess the required characteristics for hepatotropic gene delivery and may be considered for further application in vivo.

Great advances in biotechnology have allowed the construction of a computer from DNA. One of the proposed solutions is a biomolecular finite automaton, a simple two-state DNA computer without memory, which was presented by Ehud Shapiro’s group at the Weizmann Institute of Science. The main problem with this computer, in which biomolecules carry out logical operations, is its complexity – increasing the number of states of biomolecular automata. In this study, we constructed (in laboratory conditions) a six-state DNA computer that uses two endonucleases (e.g. Acu I and Bbv I) and a ligase. We have presented a detailed experimental verification of its feasibility. We described the effect of the number of states, the length of input data, and the nondeterminism on the computing process. We also tested different automata (with three, four, and six states) running on various accepted input words of different lengths such as ab , aab , aaab , ababa , and of an unaccepted word ba . Moreover, this article presents the reaction optimization and the methods of eliminating certain biochemical problems occurring in the implementation of a biomolecular DNA automaton based on two endonucleases.

The effects of short-term treatment with phenylurea (DCMU, isoproturon) and phenol-type (ioxynil) herbicides on the green alga Chlorella kessleri and the cyanobacterium Synechocystis salina with different organizations of photosystem II (PSII) were investigated using pulse amplitude modulated (PAM) chlorophyll fluorescence and photosynthetic oxygen evolution measured by polarographic oxygen electrodes (Clark-type and Joliot-type). The photosynthetic oxygen evolution showed stronger inhibition than the PSII photochemistry. The effects of the studied herbicides on both algal and cyanobacterial cells decreased in the following order: DCMU>isoproturon>ioxynil. Furthermore, we observed that the number of blocked PSII centers increased significantly after DCMU treatment (204–250 times) and slightly after ioxynil treatment (19–35 times) in comparison with the control cells. This study suggests that the herbicides affect not only the acceptor side but also the donor side of PSII by modifications of the Mn cluster of the oxygen-evolving complex. We propose that one of the reasons for the different PSII inhibitions caused by herbicides is their influence, in different extents, on the kinetic parameters of the oxygen-evolving reactions (the initial S 0 −S 1 state distribution, the number of blocked centers S B , the turnover time of S i states, misses and double hits). The relationship between the herbicide-induced inhibition and the changes in the kinetic parameters is discussed.

Rad9 protein plays an important role in cell-cycle checkpoint signal transduction in human and yeast cells, but knowledge about Rad9 in plants is limited. This study reports that the Rad9 gene of rice can generate the transcript products OsRad9.1 and OsRad9.2 through alternative splicing. OsRad9.1 , with all nine exons, is the main cell-cycle checkpoint protein involved in the response of rice to genotoxic stresses (ultraviolet radiation and antibiotic stress), environmental stresses (drought, salt, and heavy metal stress), and auxin stimuli (2,4-D, IAA, and IBA). Meanwhile, transcript isoform OsRad9.2 , which lost exon7 and exon8, showed different preferential stimulation effects on these stresses and pollen development duration. These results might indicat that besides the monitoring and repair of DNA damage, Rad9 might involve in the development of pollen.