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Bhuvana Gopalakrishnan Burachai Sonthayanon Rownak Rahmatullah Subbaratnam Muthukrishnan 《Plant molecular biology》1991,16(3):463-467
Protoplasts were prepared from barley aleurone layers using Onozuka cellulase digestion and purification through a Percoll gradient. Protoplasts prepared by this procedure had a viability ranging from 60% to 80% during the first two days of culture. They were responsive to gibberellic acid (GA) as measured by the stimulation of -amylase synthesis. The GA stimulation was counteracted by abscisic acid (ABA). In the presence of polyethylene glycol (PEG), the protoplasts took up exogenously added plasmid DNA containing the reporter gene coding for chloramphenicol acetyl transferase (CAT) linked to a 35S promoter from cauliflower mosaic virus (CaMV) or to barley -amylase gene promoters and expressed CAT activity. Therefore, barley aleurone layer protoplasts are suitable for analysis of hormoneresponsive elements in hydrolase genes. 相似文献
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Sadia Ferheen Aziz-Ur-Rehman Nighat Afza Lubna Iqbal Muhammad Azam Rasool 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):1128-1132
Galinsosides A (1) and B (2), new flavanone glucosides together with two known flavanones, 7,3′,4′-trihydroxyflavanone (3) and 3,5,7,3′,4′-pentahydroxyflavanone (4) have been isolated from an ethyl acetate- soluble fraction of Galinsoga parviflora. Their structures were assigned on the basis of spectral studies. Compound 1 showed significant antioxidant and urease inhibitory activity while compound 2 was moderately active. On the other hand, 2 showed inhibitory potential against α-glucosidase. 相似文献
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Qurra-tul-Ann Afza Gardner Hooria Younas Muhammad Akhtar 《Biochimica et Biophysica Acta - Proteins and Proteomics》2013,1834(1):182-190
Human M-proinsulin was cleaved by trypsin at the R31R32–E33 and K64R65–G66 bonds (B/C and C/A junctions), showing the same cleavage specificity as exhibited by prohormone convertases 1 and 2 respectively. Buffalo/bovine M-proinsulin was also cleaved by trypsin at the K59R60–G61 bond but at the B/C junction cleavage occurred at the R31R32–E33 as well as the R31–R32E33 bond. Thus, the human isoform in the native state, with a 31 residue connecting C-peptide, seems to have a unique structure around the B/C and C/A junctions and cleavage at these sites is predominantly governed by the structure of the proinsulin itself. In the case of both the proinsulin species the cleavage at the B/C junction was preferred (65%) over that at the C/A junction (35%) supporting the earlier suggestion of the presence of some form of secondary structure at the C/A junction. Proinsulin and its derivatives, as natural substrates for trypsin, were used and mass spectrometric analysis showed that the kcat./Km values for the cleavage were most favourable for the scission of the bonds at the two junctions (1.02 ± 0.08 × 105 s− 1 M− 1) and the cleavage of the K29–T30 bond of M-insulin-RR (1.3 ± 0.07 × 105 s− 1 M− 1). However, the K29–T30 bond in M-insulin, insulin as well as M-proinsulin was shielded from attack by trypsin (kcat./Km values around 1000 s− 1 M− 1). Hence, as the biosynthetic path follows the sequence; proinsulin → insulin-RR → insulin, the K29–T30 bond becomes shielded, exposed then shielded again respectively. 相似文献
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Calligonolides A (1) and B (2), two new butanolides, and a new steroidal ester, 3, have been isolated from the whole plant of Calligonum polygonoides, together with four known compounds, tetracosan-4-olide, beta-sitosterol and its glucoside, and ursolic acid. Their structures were elucidated by spectroscopic and mass-spectrometric studies. Compounds 1-3 showed moderate inhibitory potential against lipoxygenase from soybean. 相似文献
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M.S. Ali M. Rahmatullah Rownak Jahan H.K.M. Yusuf A.A. Chowdhury 《Enzyme and microbial technology》1979,1(2):127-128
The effect of the insecticide 2,2-dichlorovinyldimethylphosphate (DDVP) on citric acid fermentation in Aspergillus niger was studied. The appearance of citric acid in the culture medium was increasingly delayed with increasing concentration of the insecticide, and at concentrations at or above 80 μg/ml medium, citric acid production was first observed after 192 h incubation, compared with 96 h in the control flasks. The timing of the maximum rate of citric acid formation was also similarly delayed. DDVP also resulted in a delay in the utilization of inorganic phosphate by the cultures. 相似文献
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Histology of somatic embryo initiation and organogenesis from rhizome explants of Musa spp. 总被引:1,自引:0,他引:1
The origin of somatic embryos derived from rhizome explants of triploid Musa cv. Grand Nain was the subject of histological
studies during different phases of ontogenetic development. The investigation revealed that the majority of somatic embryos
showed normal root formation and consisted of highly vacuolated cells in the poorly structured shoot apex. The embryogenic
mass and somatic embryos were mostly derived from several morphologically competent cells. Single cell origin depended on
the presence of organogenetically functional vascular cells of rhizome explants and occurred infrequently. The implications
of these findings for genetic improvement of banana and plantain by in vitro mutation breeding and gene technology are discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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In southern and south-western Ethiopia, Ensete ventricosum is grown as an important starchy, staple food crop, supporting the diet of a quarter of the Ethiopian population. Due to difficulty in germinating seeds and the long vegetative period, breeding enset is extremely difficult. Adventitious buds and somatic embryos have been induced from callus derived from corm tissues and cultured on Murashige and Skoog's (MS) basal medium supplemented with benzylaminopurine (BAP) or 6 --dimethylallylamino purine 2iP. Elongation of somatic embryos was achieved on the same medium and rooting was induced on half-strength MS basal medium supplemented with IBA. No phenotypic variation was observed among more than 200 potted regenerants. The possible implications for mutation breeding in this crop are discussed.Abbreviations IAA
Indole-acetic acid
- IBA
Indole-butyric acid
- BAP
Benzylaminopurine
- 2iP
6 --dimethylallylamino purine 相似文献
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