A novel neuropeptide precursor gene is expressed in the terrestrial snail central nervous system by a group of neurons that control mating behavior

We report the isolation of a cDNA clone encoding a neuropeptide precursor named preproGFAD from the central nervous system (CNS) of the snail Helix lucorum. Analysis of the expression of this gene shows that it is neurospecific and expressed in several groups of CNS neurons. Most notable is the expression of preproGFAD gene in the right mesocerebrum, where the neurons controlling mating behavior are located. The expression in this particular region is observed in adult animals but not in juvenile ones. The preprohormone is 108 amino acids long and contains a hydrophobic leader peptide and eight Lys-Arg recognition sites for endoproteolysis. The post-translational processing of the prohormone may lead to the generation of seven tetrapeptides, Gly-Phe-Ala-Asp-COOH (GFAD). This peptide has the same sequence as two previously isolated peptides from a related snail, Achatina fulica. The first of them (achatin-I) contains D-Phe; the second (achatin-II) is its L-Phe-containing stereoisomer. Injection of synthetic D-GFAD in nanomolar concentrations into intact animals caused an increase of the heartbeat rate and opening of the genital atrium. In preparations containing CNS with intact innervation of reproductive organs, bath application of D-GFAD caused extensive movements of the penis but not of other reproductive organs. Intracellular activation of individual neurons expressing the preproGFAD gene also elicited penis movements. D-GFAD also suppressed activity of neurons modulating feeding behavior. Our data therefore indicate that the preproGFAD gene encodes the precursor of a neuropeptide that participates in the regulation of male mating behavior. © 1998 John Wiley & Sons, Inc. J Neurobiol 35: 183–197, 1998     

低频电刺激+耳穴压豆+中药汤药治疗宫内残留物的效果及对超声指标的影响

摘要 目的：探讨低频电刺激+耳穴压豆+中药汤药治疗宫内残留物的效果及对超声指标的影响。方法：选择2022年1月至12月来我院诊治的存在宫内残留物患者120例,根据随机数字表法,将120例患者分为A组、B组、C组、D组,每组30例,A组患者采用生化汤加减治疗,B组使用低频电刺激+生化汤加减治疗,C组使用耳穴压豆+生化汤加减治疗,D组低频电刺激+耳穴压豆+生化汤加减治疗。对比四组治疗前后的宫内残留物超声影像表现,对比四组的超声RI、PI水平、中医证候积分、凝血功能指标,对比四组的血β-HCG水平恢复正常时间、月经复潮时间、阴道流血持续时间、临床疗效及不良反应发生情况。结果：治疗前,四组患者均有宫内残留物,声像的图像表现为子宫局灶性增厚,子宫内膜的回声欠均匀,厚薄不均,宫腔内局部可见不均质的回声团,边界欠清晰;治疗后,四组超声检查发现部分患者无宫内残留物;部分患者的宫内残留物回声明显减低。治疗前,四组宫内残留物超声RI、PI水平、中医证候积分、凝血功能指标对比无差异（P>0.05）;治疗后,四组的RI、PI水平较治疗前明显升高,B、C、D组明显较A组高,D组明显较B、C组高（P均<0.05）;四组的阴道出血量、小腹痛、大便干、舌苔、脉象评分、全血低切粘度、全血高切粘度、纤维蛋白原较治疗前明显降低,B、C、D组明显较A组低,D组明显较B、C组低（P均<0.05）。B、C、D组的血β-HCG水平恢复正常时间、月经复潮时间、阴道流血持续时间明显较A组低,D组的明显较B、C组低（P均<0.05）;B、C组以上指标对比无差异（P>0.05）。B、C、D组的临床疗效较A组高,D组较B、C组高,四组患者的临床疗效对比无差异（P>0.05）。治疗过程中,四组均无明显不良反应,完成治疗。结论：低频电刺激+耳穴压豆+生化汤加减治疗可明显提高血瘀证宫内残留物的效果,可能与其可改善患者的凝血功能有关,阴道彩色多普勒超声可用于评估宫内残留物治疗的疗效。     

Biosynthesis of vitamin B12 by Propionibacterium freudenreichii subsp. shermanii ATCC 13673 using liquid acid protein residue of soybean as culture medium

Vitamin B12 deficiency still persists, mainly caused by low intake of animal food products affecting vegetarians, vegans, and populations of underdeveloped countries. In this study, we investigate the biosynthesis of vitamin B12 by potential probiotic bacterium using an agroindustry residue, the liquid acid protein residue of soybean (LAPRS), as a low-cost, animal derivate-free alternative culture medium. Cultures of Propionibacterium freudenreichii subsp. shermanii ATCC 13673 growing in LAPRS for vitamin B12 biosynthesis were studied using the Plackett–Burman experimental approach, followed by a central composite design 2² to optimize the concentration of significant variables. We also performed a proteolytic treatment of LAPRS and evaluated the optimized–hydrolyzed medium influence on the microbial growth and metabolism in shaker flask and bioreactor experiments. In this all-plant source medium, P. freudenreichii subsp. shermanii produced high concentrations of cells and high amounts of vitamin B12 (0.6 mg/g cells) after process optimization. These results suggest the possibility of producing vitamin B12 by a potential probiotic bacterium in a very cheap, animal derivate-free medium to address the needs of specific population groups, at the same time reducing the production costs of this essential vitamin.     

Computational Assessment of Protein–protein Binding Affinity by Reversely Engineering the Energetics in Protein Complexes

The cellular functions of proteins are maintained by forming diverse complexes. The stability of these complexes is quantified by the measurement of binding affinity, and mutations that alter the binding affinity can cause various diseases such as cancer and diabetes. As a result, accurate estimation of the binding stability and the effects of mutations on changes of binding affinity is a crucial step to understanding the biological functions of proteins and their dysfunctional consequences. It has been hypothesized that the stability of a protein complex is dependent not only on the residues at its binding interface by pairwise interactions but also on all other remaining residues that do not appear at the binding interface. Here, we computationally reconstruct the binding affinity by decomposing it into the contributions of interfacial residues and other non-interfacial residues in a protein complex. We further assume that the contributions of both interfacial and non-interfacial residues to the binding affinity depend on their local structural environments such as solvent-accessible surfaces and secondary structural types. The weights of all corresponding parameters are optimized by Monte-Carlo simulations. After cross-validation against a large-scale dataset, we show that the model not only shows a strong correlation between the absolute values of the experimental and calculated binding affinities, but can also be an effective approach to predict the relative changes of binding affinity from mutations. Moreover, we have found that the optimized weights of many parameters can capture the first-principle chemical and physical features of molecular recognition, therefore reversely engineering the energetics of protein complexes. These results suggest that our method can serve as a useful addition to current computational approaches for predicting binding affinity and understanding the molecular mechanism of protein–protein interactions.     

N-(1-Methyl)cyclopropylbenzylamine: A novel inactivator of mitochondrial monoamine oxidase

N-(1-Methyl)cyclopropylbenzylamine was synthesized and shown to inactivate pig liver mitochondrial monoamine oxidase. Inactivation is time-dependent, concentration dependent, protected by the substrate and product of the enzyme, and is not reversed by exhaustive dialysis. Unlike N-cyclopropylbenzylamine, the adduct formed between N-(1-methyl)cyclopropylbenzylamine and monoamine oxidase is stable to treatment with benzylamine. A mechanism for the inactivation is proposed.     

A model describing chemical interference caused by decomposing residues at different densities of growing plants

In literature, the biological response of plants to phytochemicals has been modelled and then used to simulate phytotoxicity caused by plant residues during decomposition. According to the resulting residue allelopathy model, stimulation dominates in the beginning of the residue decomposition process for a short while. Thereafter, severe inhibition is predicted to occur rapidly, until stimulation gradually re-emerges at the later stages of residue decomposition. Also in literature, direct chemical interference has been shown to be density-dependent; with increasing target plant density, the effects of phytochemicals are diluted. As a result, inhibition is the most probable outcome in density-dependent phytochemical interactions at low target plant densities, but phytotoxic effects often become stimulatory as target plant density increases. In this paper, these models that have been reported in literature are combined. While the original residue allelopathy model predicts inhibitory effects in most cases, the new density-dependent extension of the residue allelopathy model predicts that the density of target plants determines whether or not inhibition occurs. According to the new model, the intensity of inhibition decreases and the final stimulatory period begins earlier if target plant density increases. Therefore, combining the effects of density-dependency to the residue allelopathy model enhances our understanding of chemical interference. In addition, the new model may partially explain why several field studies have not observed chemically driven inhibitory effects similar to those observed in laboratory experiments.     

The locations of the three cysteine residues in the primary structure of the intrinsic segments of band 3 protein,and implications concerning the arrangement of band 3 protein in the bilayer

The intrinsic domains of band 3 protein contain three cysteine residues, one in a 17 kDa middle segment and two in a 35 kDa C-terminal segment. The latter are retained in an 8 kDa fragment produced by chymotrypsin treatment of ghosts. Cleavage of cysteine residues by 2-nitro-5-thiocyanobenzoic acid (NTCB) allows localization of this amino acid in the primary structure of the 8, 17, 35 and 52 (17 plus 35) kDa segments of band 3 protein. The mapping of these residues taken with other information concerning accessibility of various sites at the two sides of the membrane leads to the conclusion that band 3 protein crosses the membrane at least five times, or ten times in a dimer structure. The implications of this conclusion in terms of band 3 protein structure and function are briefly discussed.     

Utilization of 1-chloromethylsilatrane by Rhodotorula mucilaginosa

Abstract The imperfect yeast, Rhodotorula mucilaginosa utilized nitrogen of 1-chloromethylsilatrane (CMS) as a sole nitrogen source when grown on glucose, glycerol, methanol, ethanol and succinate. Under such conditions and at concentrations from 0.45 to 4.5 mM, CMS was a growth-limiting factor. Atomic absorption spectrometry revealed the accumulation of silicon compounds in the cultural liquid which were chloroform-insoluble in contrast to CMS. The following pathway of the partial decomposition of CMS is propoposed: CMS → chloromethylsilanethryol → bis(chloromethyldisiloxane) tetraol.     

Components of tomato leaf homogenate suppress responses from galeal chemoreceptors of the adult Colorado potato beetle

Abstract. Effects of both potato and tomato residues (obtained following vacuum distillation of leaf homogenate) on responses to galeal chemosensilla of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), to trans- 2-hexenol, one of the leaf alcohols that stimulate a highly uniform gustatory response in this system, are described. Tomato residue suppressed the response to hexenol in a dose-dependent manner whereas potato residue had no effect. Suppression was detectable 0.3 s after the first application began and the normal response to hexenol recovered within 2 min. Alkaloids from potato (solanine) and tomato (tomarine) also suppressed the response to hexenol but the characteristic actions of these compounds could not fully explain the activity of the tomato residue. Constituents of tomato residue, in addition to tomatine, are probably responsible for its significant effect on galeal chemosensory responses and these probably comprise a complex set of active compounds that allow the Colorado potato beetle to distinguish potato and tomato leaves.