The maltase activity of bovine serum as an aid to the study of the Amylase I locus1

A method has been described for the detection of maltase activity in starch gels. This method has been used to resolve the difficulties encountered when analysing animals with weak AmIB activity for Ami genotype. It was found that, with the herd of the Hannah Research Institute, the heterozygote excess observed could be explained largely on the basis of these weak AmIB bands.     

Electron-conformational study for the structure-hallucinogenic activity relationships of phenylalkylamines

The structure-hallucinogenic activity relationships of a series of phenylethylamine and phenylisopropylamine derivatives have been investigated in the frameworks of electron-conformational method. The calculated geometry and electronic structure parameters accompanying to each atom and bond of each molecule in view were arranged as a matrix called electron-conformational matrix of contiguity (ECMC). The features that are responsible for strong and weak activity demonstrations have been found as submatrices of ECMCs belonging to some template compounds. Two electron-conformational features present in nonhallucinogenic compounds have been revealed. A quantitative model has been improved for predicting hallucinogenic activity numerically. A test series was used to verify the results obtained.     

Induction of the differentiation of memory T killer cells with factors released from macrophage-like cell lines

Macrophage-like cell lines J774.1 and WEHI-3 as well as peritoneal exudate macrophages have been demonstrated to produce factors which induce the differentiation of memory cells into specific T killer cells in the absence of an added antigen. LPS stimulation was required for J774.1 cells and peritoneal macrophages to produce the factors but not for WEHI-3 cells. Interferon seemed to be one of the responsible factors. However, macrophages seem to produce other active factors; one has a molecular weight (MW) of more than 80,000 and lacks thymocyte mitogenic activity; another, with a weak thymocyte mitogenic activity, has a MW of 38,000 to 44,000. The low MW thymocyte mitogenic factor (interleukin-1) showed weak T killer cell differentiating activity.     

Acetylcholinesterase activity in spiral ganglion cells in rats]

Acetylcholinesterase has been demonstrated in the spiral ganglion cells by the method of Karnovsky and Roots. After incubation for 24 h the content of AchE was measured with the help of a three-stage scale. 22% of the cells showed strong, 50% medium and 28% weak AchE activity. Within the spiral ganglion perikarya, the enzyme was equally distributed.     

Analysis of the activity of promoters from two photosynthesis-related genes psaF and petH of spinach in a monocot plant, rice

The subunit III of photosystem I and ferredoxin-NADP(+)-oxidoreductase are encoded by nuclear genes, namely psaF and petH. The activity of their promoters from spinach has been evaluated in transgenic tobacco earlier. Evaluation of the activity of these Dicotyledoneae-specific promoters has been carried out in a monocot system (i.e. rice) by transient gene expression system, based on electroporation-mediated gene delivery into protoplasts from leaves and roots. It has been found that various promoter deletions show higher activity in leaf protoplasts and elements for quantitative response are widely distributed. Transgenic rice has also been produced with a petH promoter and gus reporter gene construct. Although petH promoter is a weak promoter in comparison to the 35S promoter, it expresses well in green tissues and could be useful for plant genetic engineering.     

Acetylene reduction in the rhizosphere of rice: Methods of assay

Summary A method is described for thein situ assay of acetylene reduction activity in the rhizosphere of rice involving the use of inexpensive, lightweight equipment. The assay is quick to set up and thus many replicates can be run simultaneously. Control of any acetylene-reducing blue-green algae in the assay chamber is achieved with a photosynthetically active herbicide which has no measurable effect on rhizosphere activity. Results using this method are compared with those from an excised root assay of the same plants. Only a very weak correlation between the two methods was found.     

The levo enantiomer of o,p'-DDT inhibits the binding of 17 beta-estradiol to the estrogen receptor

It has been discovered previously that the known estrogenic activity of o,p'-DDT resides with the levo enantiomer. Since it has been presumed that this relatively weak estrogenic activity of o,p'-DDT is mediated by the estrogen receptor, the ability of the resolved enantiomeric forms of o,p'-DDT to inhibit the binding of 17 beta-estradiol to the receptor was investigated. Competitive binding assays including the use of double-reciprocal plots and sucrose gradient analyses revealed that the levo and not the dextro enantiomer could inhibit the estradiol binding to the estrogen receptor. Thus the in vivo estrogenic activity of levo o,p'-DDT correlates with its apparent ability to interact with the estrogen receptor.     

The effect of weak low-frequency magnetic fields on the intracellular calcium-dependent proteinases of fish

The in vivo and in vitro effects of weak, low-frequency magnetic fields with resonance parameters for calcium ions upon intracellular calcium-dependent proteinases (calpains) in the crucian carp (Carassius carassius (L.)) and roach (Rutilus rutilus (L.)) were studied. It has been revealed that the impact of a weak lowfrequency magnetic field leads to considerable decrease in the activity of calpains in the fish skeletal muscles and brain.     

Histochemical IAA-oxidase localization in the shoot of wheat

A histochemical method for the determination of IAA-oxidase has been used in sections of various aerial parts of winter wheat plants. High IAA-oxidase activity was localized in the cell walls of sclerenchyma near the periphery of the stem, in the vascular bundle sheath of sclerenchyma and in xylem, both in the stem and in the leaf. The cell wall—bound IAA-oxidase activity therefore appeared in lignifying tissues. The staining was very weak or absent in the cell walls of parenchyma tissues and phloem. The positive reaction of the cytosol at the bulbous ends of guard cells and in the leaf primordia is presumed to be due to cytosolic IAA-oxidase. These results are discussed in relation to peroxidase localization and to our previousin vitro studies.     

Reassessment of antioxidant activity of arbutin: Multifaceted evaluation using five antioxidant assay systems

Abstract

Arbutin, a practically used skin-lightening agent, has been reported to possess a weak antioxidant activity compared to that of its precursor, hydroquinone. However, its antioxidant activity has not been systematically evaluated. Hence, this study reassessed its activity using five assay systems. Assays were first performed using model radicals, DPPH radical and ABTS^?+. Arbutin showed weak DPPH radical-scavenging activity compared to that of hydroquinone, but showed strong ABTS^?+-scavenging activity. Its activity by ORAC assay was then evaluated using a physiologically relevant peroxyl radical. Arbutin exerted weak but long-lasting radical-scavenging activity and showed totally the same antioxidant activity as that of hydroquinone. Finally, it was shown that, in two cell-based antioxidant assays using erythrocytes and skin fibroblasts, arbutin exerted strong antioxidant activity comparable or even superior to that of hydroquinone. These findings indicate that the antioxidant activity of arbutin may have been under-estimated and suggest that it acts as a potent antioxidant in the skin.     

Weak activity of haloalkane dehalogenase LinB with 1,2,3-trichloropropane revealed by X-Ray crystallography and microcalorimetry

1,2,3-Trichloropropane (TCP) is a highly toxic and recalcitrant compound. Haloalkane dehalogenases are bacterial enzymes that catalyze the cleavage of a carbon-halogen bond in a wide range of organic halogenated compounds. Haloalkane dehalogenase LinB from Sphingobium japonicum UT26 has, for a long time, been considered inactive with TCP, since the reaction cannot be easily detected by conventional analytical methods. Here we demonstrate detection of the weak activity (k(cat) = 0.005 s(-1)) of LinB with TCP using X-ray crystallography and microcalorimetry. This observation makes LinB a useful starting material for the development of a new biocatalyst toward TCP by protein engineering. Microcalorimetry is proposed to be a universal method for the detection of weak enzymatic activities. Detection of these activities is becoming increasingly important for engineering novel biocatalysts using the scaffolds of proteins with promiscuous activities.     

Studies on a trace cell lytic activity associated with alpha-lactalbumin

alpha-Lactalbumin (alpha-LA) has been examined with a new and sensitive method for determination of lysozyme activity. Samples of bovine, human, equine, and rat alpha-LA exhibited cell lytic activity, from 2 X 10(-6) to 45 X 10(-6) of the specific activity of hen eggwhite lysozyme. The activity was chromatographically inseparable from bovine and human alpha-LA. Bovine serum albumin and purified beta-lactoglobulin were inactive. The pH profiles and reaction kinetics of bovine and human alpha-LA showed differences from those of the corresponding milk lysozymes, indicating that their lytic activities were not likely to have resulted from trace lysozyme content. Thus, it appears that a weak cell lytic activity is inherent to alpha-LA.     

In vitro evaluation of bacteriostatic activity of metal complexes of amodiaquine and primaquine

Aminoquinolines are effective antimalarial agents but have weak antibacterial activity. To study the effect of metal ions on the pharmacological behaviour of amodiaquine and primaquine - drugs derived from aminoquinolines - their complexes with 16 metal ions have been screened for their bacteriostatic activity against five human pathogenic bacterial strains. It has been found that complexes of soft acid metal ions are more effective antibacterial agents (lower MIC) than others.     

Probing the elusive catalytic activity of vertebrate class IIa histone deacetylases

It has been widely debated whether class IIa HDACs have catalytic deacetylase activity, and whether this plays any part in controlling gene expression. Herein, it has been demonstrated that class IIa HDACs isolated from mammalian cells are contaminated with other deacetylases, but can be prepared cleanly in Escherichia coli. These bacteria preparations have weak but measurable deacetylase activity. The low efficiency can be restored either by: mutation of an active site histidine to tyrosine, or by the use of a non-acetylated lysine substrate, allowing the development of assays to identify class IIa HDAC inhibitors.     

Adenovirus-mediated gene transfer in primary murine adipocytes

The transfer of genes into primary murine adipocytes using an adenovirus system has been developed. A recombinant adenovirus was constructed (expressing green fluorescent protein [GFP] under the control of the strong cytomegalovirus [CMV] promoter and a luciferase reporter gene under the control of the weak adipocyte promoter keratinocyte lipid-binding protein [KLBP/FABP5]) and incubated with primary adipocytes from C57BL/6J mice. Analysis of infected cells by confocal microscopy detected GFP expression in both the cytoplasm and nucleus of adipocytes with a 64% efficiency of infection. To demonstrate the applicability of this method in the study of gene regulation, adenovirus-infected adipocytes exhibited significant levels of luciferase activity even from a weak promoter. TPA treatment of infected adipocytes increased luciferase activity, consistent with previous studies indicating that the KLBP/FABP5 gene is up-regulated by phorbol esters.These results provide an efficient, convenient, and sensitive method to transiently infect primary murine adipocytes, facilitating protein expression or permitting analysis of reporter gene activity from both viral and endogenous promoters.     

激光对蛋白质分子作用产生的混沌态

在维一蛋白质分子链模型的基础上,引入了激光与蛋白质的相互作用项。用Ｍｅｉｎｉｋｏｖ方法讨论了激光对蛋白质分子上弧立子的作用发,现在弱激光的作用下蛋白质分子内的集体振荡可能进入混沌状态。结果表明弱激光能使蛋白质变性。     

The effect of methyl-β-cyclodextrin on the stability of Bordetella pertussis filamentous haemagglutinin

Abstract It has been demonstrated that filamentous haemagglutinin (FHA) purified from Bordetella pertussis is stable on static incubation but is unstable and quickly loses HA activity when incubated with shaking. Methylβcyclodextrin (CD) was found to have a concentration-dependent stabilizing effect on FHA incubated with shaking, suggesting that the ability of CD to enhance yields of FHA in shaken cultures could be wholly or partly due to a stabilizing effect of CD on FHA. However, only weak binding of CD to FHA was demonstrated by an ultrafiltration micropartition method and binding of CD to B. pertussis cells was not related to the presence or absence of FHA on the cell surface.     

Enzymhistochemical Localization of Alkaline Phosphatases in Germinal Cysts of the Testis of the Frog Rana temporaria (Anura)

Alkaline phosphatases have been demonstrated enzymhistochemically in the testis of the common frog Rana temporaria, caught in the month of January. The follicle cells in the cyst walls and the lamina propria of the seminiferous tubules showed strong enzymatic activity; also a weak activity was observed in the peripheral region of some of the germinal cells lying within the cysts. The possible interaction of alkaline phosphatases in the transport processes across the cyst walls has been discussed.     

Ultrastructural localization of tyrosinase in the tardigrade cuticle

Tyrosinase activity has been demonstrated ultra-structurally in the cuticle of the eutardigrade Macrobiotus hufelandi. The enzyme could be localized in the outer layer (=epicuticle) of the integument. A weak deposition of reaction product was also seen in the cytoplasm of storage cells, free floating in the haemolymph.