Genetic tags applied to the European hake, Merluccius merluccius (L.)

Three biochemical gene markers test the hypothesis that the European hake, Merluccius merluccius (L.), along the west European continental shelf are one race. The three polymorphic loci were serum transferrin (Tf), eye vitreous fluid butyric esterase (Es) and liver superoxide dismutase (Sod). Five transferrin alleles, three esterase alleles and two superoxide dismutase alleles were identified. Heterogeneity tests on genotype frequency distribution for twelve areas ranging from Norway to Biscay revealed no significant variation. The results using these genetic tags are consistent with the unit race hypothesis for hake throughout the sea areas sampled.     

The null allele in the horse esterase (Es) system detected by enzyme assay and rocket immunoelectrophoresis in heterozygous animals

The detection of the recessive null allele of horse serum esterase (Es) is possible in heterozygotes Es +/EsO which by starch gel electrophoresis appear like homo-zygotes Es +/Es + .
Two methods are proposed, the titration of enzymatic activity of esterase and the immunochemical titration of esterase as antigen. These methods can be applied to solve the cases of suspect parentage or in population studies.     

Determination of metabolic resistance mechanisms in pyrethroid‐resistant and fipronil‐tolerant brown dog ticks

Rhipicephalus sanguineus (Latreille) (Ixodida: Ixodidae) is a three‐host dog tick found worldwide that is able to complete its' entire lifecycle indoors. Options for the management of R. sanguineus are limited and its' control relies largely on only a few acaricidal active ingredients. Previous studies have confirmed permethrin resistance and fipronil tolerance in R. sanguineus populations, commonly conferred by metabolic detoxification or target site mutations. Herein, five strains of permethrin‐resistant and three strains of fipronil‐tolerant ticks were evaluated for metabolic resistance using synergists to block metabolic enzymes. Synergist studies were completed with triphenyl phosphate (TPP) for esterase inhibition, piperonyl butoxide (PBO) for cytochrome P450 inhibition, and diethyl maleate (DEM) for glutathione‐S‐transferase inhibition. Additionally, increased esterase activity was confirmed using gel electrophoresis. The most important metabolic detoxification mechanism in permethrin‐resistant ticks was increased esterase activity, followed by increased cytochrome P450 activity. The inhibition of metabolic enzymes did not have a marked impact on fipronil‐tolerant tick strains.     

1H Quantitative NMR analyses of β-asarone and related compounds for quality control of Acorus rhizome herbal drugs in terms of the effects of their constituents on in vitro acetylcholine esterase activity

We used quantitative nuclear magnetic resonance analyses to measure the contents of major constituents of Acorus rhizome materials used as herbal drugs. The inhibitory effects of crude n-hexane extracts and their individual constituents on in vitro acetylcholine esterase activity were evaluated. The crude extracts had unexpectedly weak inhibitory effects (46–64% inhibition at 1.0 mg/mL), despite the high content (46–64%) of β-asarone, which independently had a potent effect (IC₅₀ 2.9 µM [0.61 µg/mL]). Further investigation revealed participation of eudesmin A, a lignan constituent, in the suppression of the inhibitory effect of β-asarone.     

Polymorphism and inheritance of serum esterases and β-globulins in the paradise fish (Macropodus opercularis; Anabantidae)

Electrophoretic variants of serum esterases and β-globulins in two subspecies of paradise fish ( Macropodus opercularis ) were studied. Four esterase loci ( Est-1, Est-2, Est-3 and Est-4 ), a single transferin ( Tf ) and another major β-globulin locus ( Bg ) were identified by segregational analysis. Est-3 seems to be a monomorphic. locus. Three alleles of Est-1 , two of Est-2 , two of Est-4 , four of Tf and two alleles of Bg were found in the laboratory population. None of these loci were closely linked. Electrophoretic patterns of F₁ hybrids confirmed the monomeric structures of each of the studied proteins. Allelic segregation at the Tf and Bg loci was normal in F₂ and backcross populations. In crosses of the two Macropodus subspecies there were deviations from Mendelian ratios because of missing recombinant esterase phenotypes. Each of these would have been homozygous Est-2^f/f . We suppose that Est-2^f/f causes lethality in the early phase of development, except in the Est-1^c/c, Est-2^f/f combination characteristic of the parental subspecies M.o. concolor .     

Linkage studies in blood biochemical polymorphic markers of rabbits

Five erythrocyte proteins (Adenosine deaminase, Ada; 6-Phosphogluconate dehydrogenase, Pgd; Esterase 1, Es-1; Esterase 3, Es-3; NADH-Diaphorase 2, Dia-2) and a serum beta-globulin protein (Esterase 7, Est-7) were studied in rabbits using starch gel electrophoresis. Samples were obtained from 317 Spanish Common individuals (38 families, 317 individuals). For the analyses of linkage, Morton's sequential probability ratio test was applied. Clear evidence for linkage between Es-1 and Est-7 (theta 0.2) was obtained, and no evidence of linkage was obtained for the remaining pairwise combinations of loci studied.     

Effects of tenuifolin extracted from radix polygalae on learning and memory: A behavioral and biochemical study on aged and amnesic mice

Although normal cognitive changes take place when a person becomes older, aging in humans is generally associated with deterioration of cognitive performance and, in particular, of learning and memory. These cognitive deficits can cause debilitating consequences due to aging. There are a number of herbal medicines which are reported to improve brain function including intelligence.In the present study, improving effects of tenuifolin, extracted from Radix Polygalae (RP), on learning and memory in aged and dysmnesia mice were determined using step-down type passive avoidance test or Y type maze trial. Oral administration of tenuifolin (0.02, 0.04, 0.08 g/kg d⁻¹, for 15 d) evidently improved the latency and number of errors in aged and dysmnesia mice. The levels of cortical acetylcholine esterase (AChE) activity and hippocampal neurotransmitters in aged mice given tenuifolin (0.02, 0.04, 0.08 g/kg d⁻¹, for 15 d) were also investigated, and increased levels of norepinephrine (NE), dopamine (DA), decreased activity of AChE were found. However, serotonin (5-HT) had no significant difference from that of aged mice given distilled water. The evident improvement of learning and memory of aged mice is carried out by the effects of tenuifolin on the three stages of memory process, that is, acquisition, consolidation and retrieval. This may do so by relatively increasing the levels of NE, DA in the hippocampus and by decreasing the activity of AChE in the cortex.     

Molecular cloning,purification, and characterization of a novel thermostable cinnamoyl esterase from Lactobacillus helveticus KCCM 11223

A gene encoding cinnamoyl esterase (CE), which breaks down chlorogenic acid (ChA) into caffeic and quinic acids, was cloned from Lactobacillus helveticus KCCM 11223. The gene with an open reading frame of 759 nucleotides was expressed in Escherichia coli, which resulted in a 51.6-fold increase in specific activity compared to L. helveticus KCCM 11223. The recombinant CE exists as a monomeric enzyme having a molecular weight of 27.4?kDa. Although the highest activity was observed at pH 7, the enzyme showed stable activity at pH 4.0–10.0. Its optimum temperature was 65°C, and it also possessed a thermophilic activity: the half-life of CE was 24.4?min at 65°C. The half-life of CE was 145.5, 80.5, and 24.4?min at 60, 62, and 65°C, respectively. The K_m and V_max values for ChA were 0.153?mM and 559.6?µM/min, respectively. Moreover, the CE showed the highest substrate specificity with methyl caffeate among other methyl esters of hydroxycinnamic acids such as methyl ferulate, methyl sinapinate, methyl p-coumarate, and methyl caffeate. Ca²⁺, Cu²⁺, and Fe²⁺ significantly reduced the relative activity on ChA up to 70%. This is the first report on a thermostable CE from lactic acid bacteria that can be useful to hydrolyze ChA from plant cell walls.