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21.
A comparative study on tyrosine oxidation was made with a pure cationic and anionic peroxidase from peanut cell culture medium. The results showed that both isozymes possessed almost identical capacity to oxidize tyrosine to dityrosine, isodityrosine and polytyrosine with the main difference being the pH optimum (pH 4 for the anionic and pH 7 for the cationic isozyme). Variation of reaction time after 1.5 h incubation had little effect on the quantity and quality of the oxidation products. On the other hand, increase of enzyme units correspondingly increased tyrosine-oxidation. The removal of heme and carbohydrate moieties from the holoenzyme arrested the reaction thereby suggesting the role played by these moieties in stabilizing the active site of peroxidase isoenzymes. Isolated cell wall extracts catalyzed the tyrosine-oxidation equally well as the purified peroxidase. Even though polyclonal antibodies against anionic peroxidase inhibited the in vitro tyrosine reaction they did not affect the tyrosine oxidation by the cell walls, while the cationic antibodies did.Abbreviations A.PRX
anionic peanut peroxidase
- C.PRX
cationic peanut peroxidase
- PcAb
polyclonal antibodies
- ELISA
enzyme-linked-immuno-sorbent-assay
- TFMS
trifluoromethane sulfonic acid 相似文献
22.
Effect of microspore stage and media on anther culture of peanut (Arachis hypogaea L.) 总被引:2,自引:0,他引:2
Martha C. Willcox Sandra M. Reed Joyce A. Burns J. C. Wynne 《Plant Cell, Tissue and Organ Culture》1991,24(1):25-28
This study was designed to study the effects of stage of microspore development and culture medium on androgenic response in peanut (Arachis hypogaea L.). Anthers of various developmental stages were cultured for 7 days, then fixed and observed cytologically. Three sets of media, involving different basal media, growth regulators, sucrose levels and glutamine concentrations, were tested. In all experiments, the stage of development of the microspores at the time of culture was highly significant. The early uninucleate microspores stage was identified as producing the highest anther response rating. The effect of media was nonsignificant in all experiments. However, the stepwise modification of the media through the course of the study resulted in an almost 8 x increase in anther response rating. Numerically, the best media tested was N6 basal medium with 1 mg 1-1 NAA, 0.1 mg 1-1 BA, 5.5% sucrose, and 3.5 g 1-1 glutamine. While no haploids were obtained, four-nucleate cells were observed, indicating the potential in peanuts for an androgenic reponse. 相似文献
23.
Jean F. Emly Wendy A. Ratcliffe Elaine Green Sarah J. Bowden David A. Heath Ann Blight Susan Hughes John G. Ratcliffe 《生物化学与生物物理学报:疾病的分子基础》1992,1180(1):58-64
The molecular forms of parathyroid hormone-related protein (PTHRP) in conditioned media from the BEN human lung cancer cell line, rat parathyroid cells (PT-r) and human keratinocytes were studied by gel-filtraton chromatography with assay of PTHRP by immunoassays and bioassay. Immunoreactivity (1–86 and 1–34) and bioactivity (1–34) in conditioned media eluted as a coincident major peak (approx. molecular mass 19–22 kDa) and there was evidence of amino-terminal species in the molecular mass range 10–16 kDa in BEN and keratinocyte media. Western blotting of PTHRP affinity purified by monoclonal antibodies directed at regions 1–34 or 37–67, identified a major species in all cell cytosols and media with an apparent molecular mass of 24–25 kDa, consistently slighty larger than recombinant PTHRP(1–141) (mobility of 21 kDa) which may represent an intact or native form of PTHRP. Additional amino-terminal species were identified in medium from keratinocytes (16 and 7 kDa), BEN cells (18 and 14 kDa) and PT-R cells (17 kDa), suggesting that processing occurs at the C-terminus and within the mid-region to form a range of amino-terminal fragments. 相似文献
24.
The determination of chlorophylls a and b together with 14CO2 fixation in the same plant tissue samples 总被引:2,自引:0,他引:2
A simple, efficient, and inexpensive method for measuring radioactivity as well as chlorophylls a and b in a large number of plant tissue samples is presented. Chlorophyll is determined following extraction with dimethyl sulfoxide or N-N'-dimethylformamide. The solvent is then evaporated on glass-fiber filters and bleached under light. The filter disks are counted together with the cleared plant material. 相似文献
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27.
Effect of Ca on composition of fat body of peanut seed 总被引:1,自引:0,他引:1
Peanut fruits were grown in nutrient media with or without Ca and in a soil with two Ca levels, from the 20th day after penetration
of the gynophore. Seed weight was smaller in the nutrient medium without Ca than in the nutrient medium with Ca, and it was
also smaller in the soil with 4 meq of exchangeable Ca (L treatment) than in the soil with 10 meq of exchangeable Ca (H treatment).
The fat body of seeds from the Ca deficient medium and the L treatment had a decreased phospholipid content and an increased
simple lipid content. In the seed from the H treatment, phosphatidylcholine increased from the 30th to 60th day, while caldiolipin
decreased. The amount of triglyceride in the simple lipid content of fat body was decreased by Ca deficiency in the nutrient
medium, whereas that of diglyceride was increased, but these effects were not observed in the fat body of the seed from the
L treatment. No effect of Ca deficiency was observed in the fatty acid composition of triglyceride. 相似文献
28.
为了验证转基因烟草中表达的外壳蛋白(CP)能够重新包被侵入的烟草花叶病毒(TMV)的假设,利用抗原表位标记的方法观察CP亚单位在病毒5′端的交换。通过PCR 方法将来源于鼠肝炎病毒(MHV) S蛋白的两个小肽段(11 a.a.和15 a.a.)的DNA序列分别插入TMV-U1 CP基因邻近3′端的两个位点,并构建了带有外源序列的TMV 侵染克隆V9 (11 a.a.)和E15 (15 a.a.)。通过体外转录反应,得到V9 RNA 及E15 RNA。突变病毒RNA 侵染烟草(Nicotiana tabacum )后表现不同特性。V9 和E15 侵染XanthiNN烟草后同野生型TMV一样产生枯斑。但是,当它们侵染Xanthinn 烟草时,V9 产生同侵染XanthiNN 烟草相同的枯斑,而E15的特性同TMV-U1几乎完全相同,能对Xanthinn 烟草进行系统侵染并在叶片中聚集大量的带有外源片段的外壳蛋白,而且病毒的结构极其稳定。V9 和E15 特性的差异可能是由于外源片段在外壳蛋白中存在位置的不同影响了外壳蛋白的结构所致 相似文献
29.
48例原发性闭经患者的细胞遗传学分析 总被引:9,自引:1,他引:8
郑克勤 李永全 潘超仁 周汝滨 廖霞 陈小萍ZHENG Ke-Qin LI Yong-Quan PAN Chao-Ren ZHOU Ru-Bin LIAO Xia CHEN Xiao-Ping 《遗传》1996,18(1):33-35
本文报告对48例原发闭经患者的临床和细胞遣传学分析,共发现染色体异常17例,占35.4%,其中包括45,X,7例;45,X/46,XX,2例;X染色体结构异常5例;核型中有Y染色体3例。讨论了原发闭经的细胞遗传学病因及异常核型与表型的关系。 相似文献
30.
将小鼠乳腺癌病毒启动子控制的细小病毒非结构蛋白基因(长5.7kb)氯化铯超速离心,纯化透析后用显微注射法导入C57BL/SJL F_1小鼠受精卵雄核,植入假孕母鼠输卵管,得成活小鼠15只。抽取鼠尾DNA,对其中10只小鼠作PCR和southern blot鉴定,其中4只(40%)整合有目的基因。对首建者B_6()的8只子代小鼠鉴定,3只(37.5%)整合有目的基因。说明导入的目的基因能传代。 相似文献