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101.
Mapping of hiv-1 Gag epitopes recognized by polyclonal antibodies using gene-fragment phage display system. 总被引:1,自引:0,他引:1
S Gupta K Arora A Sampath S S Singh A Gupta V K Chaudhary 《Preparative biochemistry & biotechnology》2001,31(2):185-200
Phage display has emerged as a powerful technique for mapping epitopes recognised by monoclonal and polyclonal antibodies. We have recently developed a simple gene-fragment phage display system and have shown its utility in mapping epitope recognised by a monoclonal antibody. In the present study, we have employed this system in mapping epitopes recognised by polyclonal antibodies raised against HIV-1 capsid protein, p24 which is derived from proteolytic cleavage of Gag polyprotein. HIV-1 gag DNA was fragmented by DNase I and the fragments (50-250 bp) were cloned into gene-fragment phage display vector to construct a library of phages displaying peptides. This phage library was used for affinity selection of phages displaying epitopes recognised by rabbit anti-p24 polyclonal antibodies. Selected phages contained sequences from two discrete regions of p24, demonstrating the presence of two antigenic regions. The DNA sequences encoding these regions were also cloned and expressed as GST fusion proteins. The immunoreactivity of these epitopes as GST fusion proteins, or as phage-displayed peptides, was comparable in ELISA system using same anti-p24 polyclonal antibodies. The results indicate that the gene-fragment based phage display system can be used efficiently to identify epitopes recognised by polyclonal antibodies, and phage displayed epitopes can be directly employed in ELISA to detect antibodies. 相似文献
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107.
Studies of mediator involvement in cooling-induced alterations of guinea pig tracheal smooth muscle contractility 总被引:1,自引:0,他引:1
R C Kolbeck B A Chaudhary W A Speir 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1988,187(1):82-88
Heat loss from airway smooth muscle is a potent stimulus which causes substantial, but poorly understood, alterations in muscle tension. This study considered the involvement of endogenous mediators in cooling-induced tension changes in incubated guinea pig trachea. Smooth muscle tension was monitored in tracheal cylinders which were carefully cooled from 37 to 30 degrees C in the presence or absence of various inotropic mediators. In our study, cooling alone, at a rate of 1 degree C/min, was associated with an average loss of smooth muscle tension of 88.2 mg. Cooling tracheal tissue that had been previously exposed to 3 X 10(-6) M histamine, however, caused an additional increase in tracheal tension of 133 mg, over and above that caused by histamine alone. In the presence of 10(-5) M prostaglandin F2 alpha, or 10(-5) M thromboxane B2, cooling was associated with respective losses of smooth muscle tension of 211.4 and 211.2 mg, as compared to the tension associated with these mediators when they were used alone under control conditions. When the speed of tracheal cooling was increased to 40 degrees C/min, there was a slight increase in tension for 20 sec followed by a pronounced and sustained relaxation. The mechanisms involved in the response of airway smooth muscle to cooling are complex. The results of our study, however, suggest that mediators may play a role in the cooling-induced alterations of airway smooth muscle tension. 相似文献
108.
Renuka Chaudhary Terje Raudsepp Xin-Yuan Guan Hongen Zhang Bhanu P. Chowdhary 《Mammalian genome》1998,9(1):44-49
Microdissected arm specific paints (ASPs) for human (HSA) chromosomes (Chrs) 2, 5, 6, 16, and 19 were used as probes on pig
(SSC) and horse (ECA) metaphase chromosomes. Regions homologous to individual human arms were delineated in the two species
studied. Of the ten ASPs used, HSA6 and 16 ASPs showed complete synteny conservation of individual arms as single blocks/arms
both in pig and horse. A similar trend was, in general, also observed for HSA19 ASPs. However, contrary to these observations,
synteny conservation of individual arms of HSA2 and HSA5 was not observed in pig and horse. The arm specific painting data,
coupled with the available gene mapping data, showed that, although HSA2 corresponded to two arms/chromosomes each in pig
and horse, the breakpoint of this synteny in humans was not located at the centromere, but at HSA2q13 band. Similarly, arm
specific paints for HSA5 showed that of the two blocks/chromosomes painted in pig and horse, one corresponded to HSA5q13-pter,
the other to HSA5q13-qter. The findings suggest that 5q13 band may also be an evolutionary break point, similar to the one
detected on HSA2q13. The microdissected human arm specific painting probes used in the present work provide more accurate
and refined comparative information on pig and horse chromosomes than that available through the use of human whole chromosome
specific paints.
Received: 1 June 1997 / Accepted: 5 September 1997 相似文献
109.
The present study focusses on the effects of pH, temperature, intensity of white, red far-red light on zygospore germination
in the filamentous green algaSpirogyra hyalina. Maximum germination of zygospores occurred at pH 8.0 and 25°C. Germination of zygospores was favored by white light at an
intensity of 3–4 klx. Red light resulted in higher germination when applied at the beginning or in the middle of the dark
period, while far-red light decreased zygospore germination. Red light in the middle of the dark period was found to be most
effective for germination. These observations suggest a possible presence of the phytochrome system in the test alga contributing
to its morphogenetic response. 相似文献
110.