[Molecular functions of polyamines in neoplastic growth and their role in control of the NF-kappaB transcription factor in experimental tumors cells].

PA were found to promote creation of the NF-kappaB complex with the correspondent DNA sequences (NRE), p50 NF-kappaB-subunit affinity with NRE is essentially magnified in PA presence. This is one of important demonstrations of PA involvement in transcription control. NF-kappaB activity in experimental mammary tumors cells was shown to depend on PA metabolism. Retardation of experimental mammary tumors growth caused by the inhibitors of PA biosynthesis was accompanied with decreased expression of protein products of the NF-kappaB-dependent genes such as c-myc, bcl-xl. It was hypothesized that under PA depletion not classic NF-kappaB (p50/p65 heterodimer) but p50/p50 homodimer is mainly created, and this homodimer, because of PA deficiency, is not able to promote transcription of the gene have been tested.

[Use of soybean trypsin inhibitor for modification of gold surface of the sensor chips in surface plasmon resonance spectrometer]. / Zastosuvannia soievoho inhibitora Trypsynu dlia modyfikatsiï poverkhni zolota sensornykh chipiv spektrometra poverkhnevoho plazmonnoho rezonansu.

Kunitz soybean trypsin inhibitor (STI) and glutaraldehyde are used to create an interlayer for proteins immobilization on the gold surface of the sensor chips of surface plasmon resonance spectrometer. Human serum albumin (HSA), goat Ig G and bovine eye lens alpha-crystallin are immobilized via the proposed interlayer. We studied the effects of the duration of storage of the sensor chips before use and pre-treatment by "piranha" solution on the STI adsorption by the gold surface. The influence of STI surface concentration, as well as the effect of the duration of storage of STI-modified sensor chips on the HSA immobilization are investigated. The binding of specific antibodies to the immobilized proteins and non-specific binding to the modified surfaces are studied. HSA immobilization on the bare gold surface is compared to that on the surfaces, modified by different methods.

[Effects of spermine and putrescine on the binding of the transcription factor NF-kappaB to specific DNA sequences]. / Vplyv sperminu ta putrestsynu na zv'iazuvannia faktora transkryptsiï NF-kappaB zi spetsyfichnymy poslidovnostiamy DNK.

Using fluorescence resonance energy transfer technique, effects of polyamines (spermine and putrescine) on the binding of p50 subunit of the nuclear transcription factor NF-kappaB to specific DNA sequences were studied in model experiments. It is demonstrated that polyamines in the concentration range from 1 to 500 mcM facilitate the binding of NF-kappB to specific DNA sequences. The data currently obtained agree with our previous predictions made by the computer modelling techniques. Our results presented in this work allow us to suggest that polyamines (excessive synthesis of which proceeds in tumor growth) may participate in the regulation of transcription of several oncogenes by the factor NF-kappaB.

[Investigation of polyamine interactions with the nuclear transcription factor NF-kappa B by computer modelling]. / Doslidzhennia vzaiemodiï poliaminiv z iadernym faktorom transkryptsiï NF-kappa B metodamy komp'iuternoho modeliuvannia.

Computer modelling is used to study interactions between polyamines and nuclear transcription factor NF-kappa B and NF-kappa B. specific DNA complex. It is shown that polyamines can regulate interaction between NF-kappa B and the specific DNA sequence by binding to p50 subunit of NF-kappa B. A possible polyamines binding site on the surface of p50 is found. Dissociation of polyamines to p50.DNA complex is modelled. Kd of spermine, spermidine and putrescine are calculated. Conformational transition of DNA.(p50)2-->DNA.p50 + p50 is simulated. Kd of complex p50.DNA is calculated in the presence and in the absence of polyamine in the binding site on the p50. It is shown that polyamines stabilizes the inter-domain interface of p50 protein due to appearance of additional electrostatic and hydrogen bonds. Shah, Thomas and Shirahata obtained the following sequence of efficiency in facilitating NF-kappa B--DNA binding: spermine > spermidine > putrescine. The sequence of affinities of polyamines to NF-kappa B that we obtained corresponds well to the former sequence from the cited work. Our results support the hypothesis that polyamines decreases the probability of spontaneous dissociation of DNA.p50 complex.