A Shift Towards Biotechnology: Social Opinion in the EU.

Consumers' attitude to genetic engineering provides information to stakeholders who are interested in its adoption, which is essential considering the emerging growth of new breeding techniques. This short article analyses, compares, and describes the knowledge, doubts, and concerns of Europeans about biotechnology and genetic engineering over the past 20 years.

Mechanisms of homocysteine toxicity in humans.

Homocysteine, a non-protein amino acid, is an important risk factor for ischemic heart disease and stroke in humans. This review provides an overview of homocysteine influence on endothelium function as well as on protein metabolism with a special respect to posttranslational modification of protein with homocysteine thiolactone. Homocysteine is a pro-thrombotic factor, vasodilation impairing agent, pro-inflammatory factor and endoplasmatic reticulum-stress inducer. Incorporation of Hcy into protein via disulfide or amide linkages (S-homocysteinylation or N-homocysteinylation) affects protein structure and function. Protein N-homocysteinylation causes cellular toxicity and elicits autoimmune response, which may contribute to atherogenesis.

Type I collagen and collagen mimetics as angiogenesis promoting superpolymers.

Angiogenesis, the development of blood vessels from the pre-existing vasculature, is a key component of embryogenesis and tissue regeneration. Angiogenesis also drives pathologies such as tumor growth and metastasis, and hemangioma development in newborns. On the other hand, promotion of angiogenesis is needed in tissues with vascular insufficiencies, and in bioengineering, to endow tissue substitutes with appropriate microvasculatures. Therefore, much research has focused on defining mechanisms of angiogenesis, and identifying pro- and anti-angiogenic molecules. Type I collagen, the most abundant protein in humans, potently stimulates angiogenesis in vitro and in vivo. Crucial to its angiogenic activity appears to be ligation and possibly clustering of endothelial cell (EC) surface alpha 1 beta 1/alpha 2 beta 1 integrin receptors by the GFPGER(502-507) sequence of the collagen fibril. However, additional aspects of collagen structure and function that may modulate its angiogenic properties are discussed. Moreover, type I collagen and fibrin, another angiogenic polymer, share several structural features. These observations suggest strategies for creating "angiogenic superpolymers", including: modifying type I collagen to influence its biological half-life, immunogenicity, and integrin binding capacity; genetically engineering fibrillar collagens to include additional integrin binding sites or angiogenic determinants, and remove unnecessary or deleterious sequences without compromising fibril integrity; and exploring the suitability of poly(ortho ester), PEG-lysine copolymer, tubulin, and cholesteric cuticle as collagen mimetics, and suggesting means of modifying them to display ideal angiogenic properties. The collagenous and collagen mimetic angiogenic superpolymers described here may someday prove useful for many applications in tissue engineering and human medicine.

[Cloning - controversies]. / Kontrowersje--klonowanie.

Cloning of the human being is not only highly controversial; in the opinion of the authors it is impossible - we are not able to reproduce human behaviour and character traits. Reproduction through cloning is limited to personal genome resources. The more important is protection of genomic characteristics as private property and taking advantage of cloning for production of the human organs directly or through xenotransplants. In this paper we present the legislation related to cloning in Poland, in the European Union and other countries. We also indicate who and why is interested in cloning.

Stress conditions applied to the interpretation of translation machinery.

Gene expression is regulated at the critical steps: a regulatory event occurs at the step which has a critical effect and is responsible for the limiting rate. Enzyme activity can be regulated at several different levels: transcriptional, translational or post-translational. In this review we describe (and illustrate with experimental data) plant stress which induces regulatory mechanisms at the translational and post-translational levels. We found evidence for autorepression regulatory system of ferritin biosynthesis. Based on the knowledge of the molecular mechanism of regulation, we believe that ferritin protects the environment against heavy metal ions and supplements biological system(s) with iron. The quinolizidine alkaloids' (QA) biosynthesis is lysine decarboxylase (LDC)-dependent. The available pool of LDC limits the conversion of lysine to cadaverine. The amount of LDC depends on transcriptional and translational efficiency. However, in the light of the presented data, we have evidence for a post-translational regulatory system, i.e. the activation of LDC from low to high activity enzyme through the conversion from higher to lower molecular weight form. The plant protection system is very efficient. Understanding of the defence systems such as plant response to stress, should provide us with a possibility of applying this knowledge in practice and finding novel applications.

Design of peptides with high affinities for heparin and endothelial cell proteoglycans.

Proteoglycan-binding peptides were designed based on consensus sequences in heparin-binding proteins: XBBXBX and XBBBXXBX, where X and B are hydropathic and basic residues, respectively. Initial peptide constructs included (AKKARA)(n) and (ARKKAAKA)(n) (n = 1-6). Affinity coelectrophoresis revealed that low M(r) peptides (600-1,300) had no affinities for low M(r) heparin, but higher M(r) peptides (2,000-3,500) exhibited significant affinities (K(d) congruent with 50-150 nM), which increased with peptide M(r). Affinity was strongest when sequence arrays were contiguous and alanines and arginines occupied hydropathic and basic positions, but inclusion of prolines was disruptive. A peptide including a single consensus sequence of the serglycin proteoglycan core protein bound heparin strongly (K(d) congruent with 200 nM), likely owing to dimerization through cysteine-cysteine linkages. Circular dichroism showed that high affinity heparin-binding peptides converted from a charged coil to an alpha-helix upon heparin addition, whereas weak heparin-binding peptides did not. Higher M(r) peptides exhibited high affinities for total endothelial cell proteoglycans (K(d) congruent with 300 nM), and approximately 4-fold weaker affinities for their free glycosaminoglycan chains. Thus, peptides including concatamers of heparin-binding consensus sequences may exhibit strong affinities for heparin and proteoglycans. Such peptides may be applicable in promoting cell-substratum adhesion or in the design of drugs targeted to proteoglycan-containing cell surfaces and extracellular matrices.

tRNA aminoacylated at high pressure is a correct substrate for protein biosynthesis.

tRNA can be aminoacylated specifically with amino acids at high pressure of 6 kbar (1 bar = 1.013 atm = 0.1 MPa = 10(5) Pa) in the absence of the specific aminoacyl-tRNA synthetase and ATP. In this paper we present new evidence obtained by HPLC chromatography and TLC analysis that the esterification reaction under pressure really takes place at the 3' end of the tRNA molecule. If so, tRNA to be aminoacylated undergoes conformational changes similar to those induced with aminoacyl-tRNA synthetase. The most important finding is that aminoacyl-tRNA obtained at high pressure binds to ribosomes and participates in the synthesis of polyphenylalanine in vitro. This is the best proof of proper charging of tRNA at high pressure.