Purification of rat adipose tissue lipoprotein lipase by affinity chromatography.

Lipoprotein lipase (EC 3.1.1.3) from rat adipose tissue was purified by affinity chromatography with heparin-Sepharose. Elution was carried out with buffered solutions of increasing NaCl molarity. Proteins without affinity for heparin were eluted with 0.5 M NaCl, while lipoprotein lipase activity was eluted as two peaks with 1.16 M NaCl (In earlier work on human adipose tissue (Etienne et al. (1974) C.R. Acad. Sc. Paris 279, 1487-1490) two fractions with lipoprotein lipase activity were also obtained). Phospholipase activity was detected in the fraction eluted with buffered 0.5 M NaCl and containing proteins without affinity for heparin. On feeding the fasting rats with fresh cream or glucose two peaks were also obtained, but the first peak had clearly increased while the second one had remained virtually unchanged.     

The major antenna complex of photosystem II has a xanthophyll binding site not involved in light harvesting.

We have characterized a xanthophyll binding site, called V1, in the major light harvesting complex of photosystem II, distinct from the three tightly binding sites previously described as L1, L2, and N1. Xanthophyll binding to the V1 site can be preserved upon solubilization of the chloroplast membranes with the mild detergent dodecyl-alpha-d-maltoside, while an IEF purification step completely removes the ligand. Surprisingly, spectroscopic analysis showed that when bound in this site, xanthophylls are unable to transfer absorbed light energy to chlorophyll a. Pigments bound to sites L1, L2, and N1, in contrast, readily transfer energy to chlorophyll a. This result suggests that this binding site is not directly involved in light harvesting function. When violaxanthin, which in normal conditions is the main carotenoid in this site, is depleted by the de-epoxidation in strong light, the site binds other xanthophyll species, including newly synthesized zeaxanthin, which does not induce detectable changes in the properties of the complex. It is proposed that this xanthophyll binding site represents a reservoir of readily available violaxanthin for the operation of the xanthophyll cycle in excess light conditions.     

Chick embryo cardiocytes in culture synthesize proteins not present in embryonic heart

Proteins synthesized by cardiocytes isolated from 11d embryonic hearts and cultured $\text{in vitro}$ have been compared with proteins present in the 11d embryonic heart. It is shown that cultured cardiocytes synthesize two new proteins, C₁ and C₂ with a molecular weight of 27 500 and pI of 6.35 and 6.05 respectively. The synthesis of these proteins is associated with the appearance of new RNA species. This induction is not related to the conditions of culture since it occurs with either aggregated cardioacytes grown in suspension or cardiocytes grown in monolayer. Finally no other embryonic cell types seem to synthesize these proteins.     

Association Between Mobile Phone Radiation Exposure and the Secretion of Melatonin and Cortisol,Two Markers of the Circadian System: A Review

The extremely important use of mobile phones in the world, at all ages of life, including children and adolescents, leads to significant exposure of these populations to electromagnetic waves of radiofrequency. The question, therefore, arises as to whether exposure to these radiofrequencies (RFs) could lead to deleterious effects on the body's biological systems and health. In the current article, we review the effects, in laboratory animals and humans, of exposure to RF on two hormones considered as endocrine markers: melatonin, a neurohormone produced by the pineal gland and cortisol, a glucocorticosteroid synthesized by the adrenal glands. These two hormones are also considered as markers of the circadian system. The literature search was performed using PubMed, Medline, Web of Sciences (ISI Web of Knowledge), Google Scholar, and EMF Portal. From this review on RF effects on cortisol and melatonin, it appears that scientific papers in the literature are conflicting, showing effects, no effects, or inconclusive data. This implies the need for additional research on higher numbers of subjects and with protocols perfectly controlled with follow‐up studies to better determine whether the chronic effect of RF on the biological functioning and health of users exists (or not). Bioelectromagnetics. 2021;42:5–17. © 2020 Bioelectromagnetics Society     

Measuring cortisol in fish scales to study stress in wild tropical tuna

Environmental Biology of Fishes - Cortisol is recognized as a physiological indicator of stress in fish. However, this hormone is typically measured in plasma samples. In this study, cortisol...     

The Crown Pearl: a draft genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758)

Since historical times, the inherent human fascination with pearls turned the freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) into a highly valuable cultural and economic resource. Although pearl harvesting in M. margaritifera is nowadays residual, other human threats have aggravated the species conservation status, especially in Europe. This mussel presents a myriad of rare biological features, e.g. high longevity coupled with low senescence and Doubly Uniparental Inheritance of mitochondrial DNA, for which the underlying molecular mechanisms are poorly known. Here, the first draft genome assembly of M. margaritifera was produced using a combination of Illumina Paired-end and Mate-pair approaches. The genome assembly was 2.4 Gb long, possessing 105,185 scaffolds and a scaffold N50 length of 288,726 bp. The ab initio gene prediction allowed the identification of 35,119 protein-coding genes. This genome represents an essential resource for studying this species’ unique biological and evolutionary features and ultimately will help to develop new tools to promote its conservation.     

Purification and cDNA Cloning of Antimicrobial Peptides from the Skin Secretion of the Chinese Frog Rana chensinensis

The skin secretions of amphibians are a rich source of bioactive peptides. We isolated chensirin-1 and chensirin-2 from the skin secretion of the Chinese frog Rana chensinensis. Sephadex-G-50 and RP-HPLC were employed to purify these peptides. The amino acid sequences of these peptides were VLPLVGNLLNDLLGE and IIPLPLGYFAKKT, respectively, as determined by Edman degradation. The molecular weights were 1578.7 and 1460.8 Da, respectively, as analyzed by HPLC-ESI-MS. The chensirin cDNA was cloned by 5′ and 3′ amplification of cDNA ends, synthesized and purified. The antibacterial activities of the chensirins were tested using minimum inhibitory concentration, the results indicated that chensirins inhibit the growth of gram-negative and gram-positive bacteria. Among them, chensirin-1 is a novel peptide with a higher antibacterial activity compared to other similar antimicrobial peptides. These low molecular weight peptides with good antimicrobial efficacy are considered potential sources for developing new antimicrobial agents to improve traditional drug resistance.