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81.
The effects on olfaction of N-ethylmaleimide (NEM), a specificreagent of free sulfhydryl groups, were studied in the mothMamestra brassicae. The antennae of male M.brassicae bear twotypes of specialist receptor neurons involved in pheromone communication.One type is tuned to (Z)-11-hexadecenyl acetate (Z11-16:Ac),the main pheromone component; the second type is tuned to (Z)-9-tetradecenylacetate (Z9-14:Ac), an interspecific inhibitor not producedby the females of this species. Vapours of NEM irreversiblyinhibited the electro-antennographic (EAG) responses to Z11-16:Acand Z9-14:Ac. When Zll-16:Ac was applied before and during NEMtreatment, the responses to Z9-14:Ac were preserved and someprotection was observed in the responses to Zll-16:Ac. In return,Z9-14:Ac partially prevented the disappearance of responsesto Zll-16:Ac but not to Z9-14:Ac. A third compound, hexadecylacetate (16:Ac), found in the pheromone gland, but not detectedby the antennal receptors, did not prevent the inhibition causedby NEM. 相似文献
82.
Alain F. Chaffotte Mario M. Zakin Michel E. Goldberg 《Biochemical and biophysical research communications》1980,92(2):381-388
In order to test if the α and β2 subunits of tryptophan synthetase and tryptophanase, three proteins involved in the metabolism of tryptophan in Escherichia coli K 12, have some common structural features reflecting an evolutionary filiation, an immunochemical comparison of these enzymes has been made using antibodies directed against either the native or the denatured β2 protein. The lack of cross-reactivity observed in the case of the three proteins studied, even when in their denatured state, suggests that, despite their functional relationships, they probably do not derive from a common ancestor. 相似文献
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N. Jacobs Roland Greimers Alessandra Mazzoni Mohamed Trebak Nicole Schaaf-Lafontaine Jacques Boniver Michel P. Moutschen 《Cancer immunology, immunotherapy : CII》1996,42(6):369-375
In this study we have specifically investigated the participation of T cells in the cytotoxic activity of peripheral blood
lymphocytes (PBL) activated by interleukin-2 (IL-2, 50 U/ml) alone or in combination with an anti-CD3 mAb (BMA030, 10 ng/ml,
IgG2a). Purified CD3+ T cells, incubated in the presence of the anti-CD3 mAb for 4 days, mediated a cytotoxic activity against HL60 and U937 tumor
cell lines. Several findings suggested the involvement of a redirected-cytotoxicity phenomenon, since the lytic process was
restricted to target cell lines bearing the high-affinity Fcγ receptor (FcγRI) and T lymphocytes stimulated by IL-2 alone
did not lyse these cell lines. Furthermore, anti-CD3 mAb F(ab′)2, anti-CD3 IgG1 (UCHT1), phytohemagglutinin or staphylococcal enterotoxin A did not induce a similar cytotoxic activity in
T lymphocytes. The cytotoxic process occurred in the presence of a very low level of anti-CD3 antibodies (in the nanomolar
range). The cytotoxic activity of T cells stimulated by IL-2 or by IL-2 + BMA030, against OVCAR-3 cells (MOv18+ ovarian tumor cell line), was also compared in the presence of a bispecific antibody (OC/TR, anti-CD3 × MOv18). The stimulation
by IL-2 + BMA030 induced approximately a twofold higher cytotoxic activity than IL-2-activated T cells. This could be related
to the state of activation of effector cells stimulated by IL-2 + BMA030, since the phenotypic analysis showed an increased
proportion of T cells expressing several activation/differentiation markers (CD25, HLA-DR, CD45R0, adhesion molecules). These
findings could be applied to the design of therapeutic protocols using anti-CD3 ×antitumoral bispecific antibodies.
Received: 6 December 1995 / Accepted: 4 June 1996 相似文献
86.
Growth of the hopanoid-producing bacterium Zymomonas mobilis was inhibited at low concentrations of the cationic detergent octadecyltrimethylammoniumchloride (OTAC). A relationship between sensitivity of Zymomonas mobilis to OTAC, presence of hopanoids and ethanol tolerance was postulated. Mutants resistant to OTAC were isolated from strains ZM1 and ZM4. They did not present any alteration of the hopanoid content and their squalene cyclases showed the same sensitity to OTAC as the parent enzymes. Resistance to OTAC paralleled pleiotropic effects including, enhanced accessibility of the membrane-bound alkaline phosphatase, important release of proteins from cells by Tris/HCl treatment, increased resistance to antibiotics and increased sensitivity to ethanol. In addition, OTACR mutants were also characterized by the synthesis or the overproduction of an outer membrane protein (F53) not detected on 2D-PAGE maps of parent strains and by a normal heat shock response. The role of hopanoids, heat shock proteins, protein F53 and membrane organization in ethanol tolerance is discussed.Abbreviations OTAC
octadecyltrimethylammoniumchloride
- SLS
sodium lauryl sarcosinate 相似文献
87.
Molecular profiling of CD8 T cells in autochthonous melanoma identifies Maf as driver of exhaustion 下载免费PDF全文
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