摘要:

AbstractThe life and work of Josef Rudinger (1924–1975), a key figure in the history of peptide science, are outlined. Copyright © 2004 European Peptide Society and John Wiley&Sons, L

ISSN:1075-2617    

DOI:10.1002/psc.567

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractMaculatin 1.1 (Mac) is a cationic antibacterial peptide isolated from the dorsal glands of the tree frog,Litoria genimaculata, and has a sequence of GLFGVLAKVAAHVVPAIAEHF‐NH2. A short peptide lacking theN‐terminal two residues of Mac was reported to have no activity. To investigate the structure–activity relationship in detail, several analogs and related short peptides of Mac were synthesized. CD measurement showed that all the peptides took more or less an α‐helical structure in the presence of anionic lipid vesicles. Analogs which are more basic than Mac had strong antibacterial and hemolytic activities, while short peptides lacking one or two terminal residues exhibited weak or no activity. Outer and inner membrane permeabilization activities of the peptides were also reduced with shortening of the peptide chain. These results indicate that the entire chain length of Mac is necessary for full activity, and the basicity of the peptides greatly affects the activity. Copyright © 2004 European Peptide Society and John Wiley&

ISSN:1075-2617    

DOI:10.1002/psc.560

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractTat cell‐penetrating peptide (GRKKRRQRRRPPQG) is able to translocate and carry molecules across cell membranes. Using CD spectroscopy the conformation of this synthetic peptide was studied in aqueous and membrane‐mimicking, micellar SDS solutions at different temperatures. The CD spectrum of the Tat cell‐penetrating peptide in SDS micellar solution was virtually unchanged from that in aqueous solution, and at low temperature it was close to that of a poly(proline) II helix. Copyright © 2004 European Peptide Society and John Wiley&Son

ISSN:1075-2617    

DOI:10.1002/psc.558

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractElastin is one of the most significant components of the extracellular matrix, which supports the stretchiness of the blood vessels via its helical structure and cross‐links. Enzymatic decomposition of this protein could induce chemotactic responses of cell populations in the surrounding tissues by several peptide sequences, e.g. XGXXPG. In our present work the VGVAPG variant and its oligomers were studied. The objective of the experiments was to learn (i) whether the chemotactic effect of these peptides is general in different levels of phylogeny; (ii) whether increasing the number of monomer units influences the chemotactic behaviour of the cell? The trimer had the strongest chemoattractant effect in a wide concentration range (10−12–10−7M), while the monomer and the pentamer were chemorepellent. All tri‐, tetra‐, penta‐ and hexamers could chemotactically select subpopulations with a high chemotactic responsiveness to the identical peptide, in the long term. With regard to its repellent effect, the pentamer had a negative effect on phagocytosis. All six oligomers had a growth‐promoter effect inTetrahymena. The characteristic cell‐physiological effects of VGVAPG oligomers signal that molecules of the extracellular matrix can induce identical responses even in lower levels of phylogeny, e.g. in the Ciliates. Copyright © 2004 European Peptide Society and Jo

ISSN:1075-2617    

DOI:10.1002/psc.517

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractProstate‐specific antigen (PSA), a member of the kallikrein sub‐group of the trypsin serine protease family, is a widely used marker for prostate cancer. Several sequences with specific binding to PSA have been identified by using phage display peptide libraries. The GST‐fusion proteins of the characterized sequences have been shown to increase the enzyme activity of PSA to a synthetic substrate. The corresponding three cyclic synthetic analogues CVFTSNYAFC (A‐1), CVFAHNYNYLVC (B‐2) and CVAYCIEHHCWTC (C‐4) have similar PSA promoting activity. Despite differences in the amino acid sequences, all three peptides bind to the same region of PSA. The conformation of the peptides was investigated by proton NMR spectroscopy. In addition, alanine replacement was used to characterize the prerequisites for binding. It is proposed that interactions with PSA are based on the aromatic and hydrophobic features of the amino acid side chains. Furthermore, it is suggested that peptides form β–turn structures forced by cysteine bridges directing important aromatic side chains to the same side of the turn‐structure. Copyright © 2004 European Peptide Society and Joh

ISSN:1075-2617    

DOI:10.1002/psc.557

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractStructural parameters, originating from x‐ray crystallographic data, have been compiled for 13 derivatives of amino acids, peptides and related compounds, which contain a total of 14 Fmoc‐NH– moieties. For these moieties, molecular geometries and conformations—described by the ω0, θ1, θ2and θ3′torsion angles—were analysed and compared with the corresponding parameters for the Z‐NH– and Boc‐NH– moieties (290 and 553, respectively). To gain a deeper insight into the conformational features of the Fmoc‐NH– moiety,ab initiofree molecule calculations were performed for fully relaxed minima. Also the potential energy surface as a function of the torsion angles (θ3′, θ2) was generated. The conformational features of the Fmoc‐NH– moiety: (i) two possible values for the angle ω0(∼180° or, rarely, ∼0° ) and (ii) the angle θ1= 180° ± 15°, are common to the Z‐NH– and Boc‐NH– systems. By contrast, the θ2and θ3angles in the Fmoc, Z and Boc groups differ essentially. In the Fmoc groups θ2mostly has values of 180° ± 30° and values up |115°| seem to be forbidden, whereas fewer than half of the Z groups adopt θ2∼ 180° and the remainder have θ2in the range of |90° ± 20°|. On the other hand, the Boc methyl groups are staggered. The θ3values observed for Fmoc are limited to the regions of 180° ± 20° and |60° ± 20°|, while for the Z group a variety of θ3occurs. The orientation of the fluorenyl vs the urethane function is mostlytrans. Our results suggest a lower conformational flexibility for the Fmoc group compared with that of the Z group. Our calculations confirm that the observed conformational features for the Fmoc‐NH– moiety are inherent properties. The Fmoc‐NH– moiety in crystals involves the participation of its OC–NH functional

ISSN:1075-2617    

DOI:10.1002/psc.555

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractPhytosulfokine‐α (PSK‐α), a sulfated growth factor (H‐Tyr(SO3H)‐Ile‐Tyr(SO3H)‐Thr‐Gln‐OH) universally found in both monocotyledons and dicotyledons, strongly promotes proliferation of plant cells in culture. In our studies on structure/activity relationship in PSK‐α the synthesis of a series of analogues was performed: [H‐D‐Tyr(SO3H)1]‐ (9), [H‐Phe(4‐SO3H)1]‐ (10), [H‐D‐Phe(4‐SO3H)1]‐ (11), [H‐Phg(4‐SO3H)1]‐ (12), [H‐D‐Phg(4‐SO3H)1]‐ (13), H‐Phe(4‐NHSO2CH3)1]‐ (14), [H‐D‐Phe(4‐NHSO2CH3)1]‐ (15), [H‐Phe(4‐NO2)1]‐ (16), [H‐D‐Phe(4‐NO2)1]‐ (17), [H‐Phg(4‐NO2)1]‐ (18), [H‐D‐Phg(4‐NO2)1]‐ (19), [H‐Hph(4‐NO2)1]‐ (20), [H‐Phg(4‐OSO3H)1]‐ (21), [Phe(4‐NO2)3]‐ (22), [Phg(4‐NO2)3]‐ (23), [Hph(4‐NO2)3]‐ (24), [H‐Phe(4‐SO3H)1, Phe(4‐SO3H)3]‐ (25) [H‐Phe(4‐NO2)1, Phe(4‐NO2)3]‐ (26), [H‐Phg(4‐NO2)1, Phg(4‐NO2)3]‐ (27), [H‐Hph(4‐NO2)1, Hph(4‐NO2)3]‐ (28) and [Val3]‐ PSK‐α (29). For modification of the PSK‐α peptide chain the novel amino acids and their derivatives were synthesized, such as: H‐L‐Phg(4‐SO3H)‐OH (1), H‐D‐Phg(4‐SO3H)‐OH (2), Fmoc‐Phg(4‐SO3H)‐OH (3), Fmoc‐D‐Phg(4‐SO3H)‐OH (4), Boc‐Phg(4‐NHSO2CH3)‐OH (5), Boc‐D‐Phg(4‐NHSO2CH3)‐OH (6) Boc‐Phe(4‐NHSO2CH3)‐OH (7), and Boc‐D‐Phe(4‐NHSO2CH3)‐OH (8). Peptides were synthesized by a solid phase method according to the Fmoc procedure on a Wang‐resin. Free peptides were released from the resin by 95% TFA in the pr

ISSN:1075-2617    

DOI:10.1002/psc.492

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY

摘要:

AbstractThe preparation and characterization of two novel LysB29 selectively labelled fluorescent derivatives of human insulin are described. Two probes were chosen: 4‐chloro‐7‐nitrobenz‐2‐oxa‐1,3‐diazole (NBD) and 7‐methoxycoumarin‐4‐acetic acid (MCA), which have a relatively small, compact structure and are able to react with amino groups to form highly fluorescent derivatives. The combination of solid phase peptide synthesis and enzymatic semisynthesis was chosen for preparation of these fluorescent derivatives. Using two different protocols of solid‐phase peptide synthesis, two fluorescent octapeptides were prepared corresponding to the position B23–B30 of human insulin, each with a different fluorescent label, NBD or MCA, on the ε‐amino group of lysine. Then, the fluorescent octapeptides were coupled to desoctapeptide‐(B23–B30)‐insulin by a trypsin catalysed reaction. The receptor binding affinities of two novel fluorescent derivatives of human insulin with NBD and MCA (HI‐NBD and HI‐MCA) were determined on rat adipose tissue plasma membranes. Both fluorescent insulins, HI‐NBD and HI‐MCA, had only slightly reduced binding affinity and will be used for studying the interaction of insulin with its receptor. Copyright © 2004 European

ISSN:1075-2617    

DOI:10.1002/psc.556

出版商:John Wiley&Sons, Ltd.    

年代:2004

数据来源: WILEY