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1.
M. Filek J. Biesaga-Kościelniak I. Marcińska M. Cvikrová I. Macháčková J. Krekule 《Biologia Plantarum》2010,54(3):483-487
The contents of endogenous free and conjugated polyamines, putrescine (Put) and spermidine (Spd), were determined during 9
week of vernalization (at 5 °C) in winter wheat seedlings cultivated on Murashige and Skoog media without (MS0) and with 2
mg dm−3 zearalenone (MSZEN). At the 4th week of chilling treatment, which is sufficient to induce generative development in 30 % of plants, the marked increase in
free and conjugated forms of Put and free Spd were observed. The presence of ZEN in medium significantly accelerated the vernalization.
About 20 % of plants treated with ZEN flowered already after 2 weeks and 40 % after 3 weeks of chilling. Significantly higher
content of free Put was determined in roots grown on MSZEN compared with MS0 during the first 5 weeks of vernalization with
maximum at the 4th week. After germination, a marked decrease in free Spd content was observed both in plants grown on MS0 and MSZEN. Application
of ZEN significantly slowed down the Spd decline in leaves and roots during the first and second week of vernalization. The
content of Spd and its conjugates decreased in vernalized plants after 1 week of cultivation at 20 °C. 相似文献
2.
The production of L-lysine fromDL-α-amino-ε-caprolactam (DL-ACL) by new strains producingL-α-amino-ε-caprolactamase and aminocaprolactam racemase is described. Optimal conditions for hydrolysis ofL-ACL byCryptococcus sp. and for racemization of ACL by cells of a strain isolated in nature and identified asPseudomonas sp. were determined. Synthesis ofL-α-amino-ε-caprolactamase is induced byDL-ACL orL-lysine with the same effectivity. A positive effect of phosphates (potassium salts) on reduction of the induction lag was
detected, the synthesis of this enzyme was found to be repressed by glucose and some possibilities of the reversion of this
repressive effect were demonstrated. Under conditions optimal for the production of both enzymes a quantitative theoretical
conversion of 10 % aqueousDL-ACL toL-lysine by a mixture of native cells in a mass ratio of 1: 2 (producer of ACL-hydrolase to producer of ACL-racemase) occurred
in 8 h at 40 °C and pH 8.0 相似文献
3.
Calcium channel blockers, verapamil, nitrendipin and nifedipin, and cyclosporin A inhibited growth of colonies ofBotrytis cinerea in a concentration-dependent manner and simultaneously induced morphological changes of its hyphal tips. Exogenous calcium
at the concentration of 100 mmol/L decreased the growth-inhibitory effects of channel blockers and cyclosporin A; however,
at the concentration of 500 mmol/L Ca2+ their inhibitory effects were increased. At the latter concentration, calcium partly reversed the morphogenic effects of
the blockers but not of cyclosporin A. 相似文献
4.
Ruth Duncan Pavla Rejmanova Jindrich Kopeček John B. Lloyd 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(1):143-150
Synthetic 125I-labelled N-(2-hydroxypropyl)methacrylamide copolymers containing four different, potentially degradable peptidyl side chains were incubated with rat visceral yolk sacs cultured in vitro. All copolymers were captured by fluid-phase pinocytosis and three of the side chains were susceptible to lysosomal hydrolysis, resulting in release of [125I]iodotyrosine back into the culture medium. Uptake and degradation was completely inhibited by 2,4-dinitrophenol. The thiol-proteinase inhibitor leupeptin did not affect the rate of pinocytosis, but caused different degrees of inhibition of hydrolysis depending on side chain composition. 相似文献
5.
6.
Summary Two siblings with a short-limb dwarfing condition which we call acromesomelic dysplasia, Hunter-Thompson type are reported. Abnormalities are limited to the limbs and limb joints in this severe form of dwarfism. The middle and distal
segments of the limbs are most affected. The lower limbs are more affected than the upper. We are aware of one previously
published case of this entity reported by A. G. W. Hunter and M. W. Thompson in 1976. Dislocations of the elbows and ankles
were present in all three patients and dislocations of the hips and knees in two. One of the siblings who did not have hip
and knee dislocations clinically resembled Grebe chondrodysplasia, another severe acromesomelic dwarfing condition. However,
radiological analysis suggests that while acromesomelic dysplasia, Hunter-Thompson type and Grebe chondrodysplasia are related,
they are not identical. Grebe chondrodysplasia has been established as an autosomal recessive trait. It appears probable that
the entity we describe has the same mode of genetic transmission. 相似文献
7.
8.
J. Nečas 《Biologia Plantarum》1970,12(5):359-367
Populations of theChloretta vulgaris Beijeb. strain ?esnokov “V” clones (progenies of single cells) grown up from cells treated by chemical mutagens were cultivated on the surface of solid media. The differentiation of growth types according to their growth rates in the populations originating from the same sample of cells but growing under different conditions was compared. The strain studied exhibited much greater growth rate variability on the complete medium than on the minimal one. Short time changes of light regime during the cultivation for the purpose of inducing reparation processes in the mutagen damaged cells did not manifest themselves significantly in the composition of resulting clonal populations. The possibility of selection of growth types under conditions studied was considered. 相似文献
9.
Hana Votavová Vladimír Gut Karel Bláha Jaroslav Šponar 《International journal of biological macromolecules》1982,4(6):341-346
DNA complexes with polypeptides (Lys-Ala-Ala)1)] and (Lys-Ala-Ala)34 have been studied using the methods of thermal melting and circular dichroism. Derivative melting curves of (Lys-Ala-Ala)10 DNA differed substantially from those of (Lys-Ala-Ala)34 prepared either by salt gradient dialysis or by direct mixing. Melting curves of the former complex were unimodal or bimodal with Tm increasing continuously withn input lysin-to-DNA phosphate ratio (r); those of the latter complex consisted of three separate transitions with Tm values almost independent of r. Complete reversibility of binding in the (Lys-Ala-Ala)10-DNA system but a slow redistribution of (Lys-Ala-Ala)34 on DNA at low temperature were found in the redistribution experiments Much faster redistribution from denatured to native DNA occurs at the temperature of melting, contributing to the unusual trimodal melting pattern. Circular dichroism curves are very similar for both complexes and indicate little change of DNA conformation upon polypeptide binding. 相似文献
10.
Aileen F. G. Bongat Rina Saksena Roberto Adamo Yukari Fujimoto Zenyu Shiokawa Dwight C. Peterson Koichi Fukase Willie F. Vann Pavol Kováč 《Glycoconjugate journal》2010,27(1):69-77
Using recombinant tetanus toxin HC fragment (rTT-HC) as carrier, we prepared multimeric bivalent immunogens featuring the synthetic hexasaccharide fragment of O-PS of Vibrio cholerae O:1, serotype Ogawa, in combination with either the synthetic hexasaccharide fragment of O-PS of Vibrio cholerae O:1, serotype Inaba, or a synthetic disaccharide tetrapeptide peptidoglycan fragment as adjuvant. The conjugation reaction
was effected by squaric acid chemistry and monitored in virtually real time by SELDI-TOF MS. In this way, we could prepare
well-defined immunogens with predictable carbohydrate–carrier ratio, whose molecular mass and the amount of each saccharide attached could be independently determined. The ability to prepare such neoglycoconjugates opens unprecedented possibilities
for preparation of conjugate vaccines for bacterial diseases from synthetic carbohydrates. 相似文献