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DYNORPHIN-A-(1-13)-TYR14-LEU15-PHE16-ASN17-GLY18-PRO19 - A POTENT AND SELECTIVE KAPPA-OPIOID PEPTIDE

EUROPEAN JOURNAL OF PHARMACOLOGY 1991年第2期196卷 161-167页

作者： MARTINKA, GP JHAMANDAS, K SABOURIN, L LAPIERRE, C LEMAIRE, S UNIV OTTAWA FAC MED DEPT PHARMACOL OTTAWA K1H 8M5 ONTARIO CANADA QUEENS UNIV DEPT PHARMACOL & TOXICOL KINGSTON K7L 3N6 ONTARIO CANADA

Dynorphin A-(1-13)-Tyr14-Leu15-Phe16-Asn17-Gly18-Pro19 (dynorphin Ia: a peptide derived from the structure of adrenal dynorphin I) was synthesized by the solid-phase procedure. The product was purified and compared with dynorphin A-(1-13) and [D-Pro10]dynorphin A-(1-11) for its ability to inhibit the electrically evoked contractions of the guinea pig ileum (GPI) and mouse vas deferens (MVD) and to compete with the binding of [H-3]ethylketocyclazocine (kappa ligand), [H-3][D-Ala2,MePhe4,Glyol5]enkephalin (mu ligand) and [H-3][D-Ser2,Thr6]Leu-enkephalin (delta ligand) to membrane preparations of the guinea pig cerebellum or rat brain. Additionally, the antinociceptive effects of the synthetic peptide were assessed in rat paw-pressure and tail-flick tests. In the GPI, dynorphin Ia possessed a relative potency (IC50 0.5 nM) that was comparable to that of [D-Pro10]dynorphin A-(1-11) (IC50 0.5 nM) or dynorphin A-(1-13) (IC50 0.7 nM). In the delta specific MVD assay, dynorphin Ia displayed a reduced potency (IC50 235 nM) as compared with that of dynorphin A-(1-13) (IC50 20 nM) or [D-Pro10]dynorphin A-(1-11) (IC50 46 nM). The affinity of dynorphin Ia for the kappa site in the guinea pig cerebellum (K(i) 0.25 nM) was comparable to those of dynorphin A-(1-13) (K(i) 0.11 nM) and [D-Pro10]dynorphin A-(1-11) (K(i) 0.10 nM). However, the peptide possessed reduced affinities for the mu (K(i) 6.7 nM) and delta (K(i) 71 nM) opioid receptors as compared with [D-Pro10]dynorphin A-(1-11) (K(i) 1.7 and 1.5 nM) an dynorphin A-(1-13) (K(i) 0.5 and 4.4 nM, respectively). Finally, low doses (2.2-8.8 nmol) of intrathecal dynorphin Ia caused a potent and selective antinociceptive effect in the paw-pressure assay and not impair motor activity or cause any significant change of blood pressure. These results indicate that dynorphin Ia possesses the biological profile of a potent and selective kappa opioid agonist.

关键词： DYNORPHIN structure-function relationships KAPPA-OPIOID RECEPTORS ANTINOCICEPTION

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EVOLUTION OF THE CYTOCHROME-B GENE OF MAMMALS

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JOURNAL OF MOLECULAR EVOLUTION 1991年第2期32卷 128-144页

作者： IRWIN, DM KOCHER, TD WILSON, AC Division of Biochemistry and Molecular Biology University of California Berkeley USA

With the polymerase chain reaction (PCR) and versatile primers that amplify the whole cytochrome b gene (approximately 1140 bp), we obtained 17 complete gene sequences representing three orders of hoofed mammals (ungulates) and dolphins (cetaceans). The fossil record of some ungulate lineages allowed estimation of the evolutionary rates for various components of the cytochrome b DNA and amino acid sequences. The relative rates of substitution at first, second, and third positions within codons are in the ratio 10 to 1 to at least 33. For deep divergences (> 5 million years) it appears that both replacements and silent transversions in this mitochondrial gene can be used for phylogenetic inference. Phylogenetic findings include the association of (1) cetaceans, artiodactyls, and perissodactyls to the exclusion of elephants and humans, (2) pronghorn and fallow deer to the exclusion of bovids (i.e., cow, sheep, and goat), (3) sheep and goat to the exclusion of other pecorans (i.e., cow, giraffe, deer, and pronghorn), and (4) advanced ruminants to the exclusion of the chevrotain and other artiodactyls. Comparisons of these cytochrome b sequences support current structure-function models for this membrane-spanning protein. That part of the outer surface which includes the Q(o) redox center is more constrained than the remainder of the molecule, namely, the transmembrane segments and the surface that protrudes into the mitochondrial matrix. Many of the amino acid replacements within the transmembrane segments are exchanges between hydrophobic residues (especially leucine, isoleucine, and valine). Replacement changes at first and second positions of codons approximate a negative binomial distribution, similar to other protein-coding sequences. At four-fold degenerate positions of codons, the nucleotide substitutions approximate a Poisson distribution, implying that the underlying mutational spectrum is random with respect to position.

关键词： POLYMERASE CHAIN REACTION DIRECT SEQUENCING MITOCHONDRIAL DNA HOOFED MAMMALS CETACEANS MOLECULAR PHYLOGENY EVOLUTIONARY RATES BASE COMPOSITION structure-function relationships

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SURFACTANT PROTEIN-B - LIPID INTERACTIONS OF SYNTHETIC PEPTIDES REPRESENTING THE AMINO-TERMINAL AMPHIPATHIC DOMAIN

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1991年第16期88卷 7451-7455页

作者： BRUNI, R TAEUSCH, HW WARING, AJ Department of Pediatrics King/Drew Medical Center University of California School of Medicine Los Angeles 90059.

The mechanisms by which pulmonary surfactant protein B (SP-B) affects the surface activity of surfactant lipids are unclear. We have studied the peptide/lipid interactions of the amino-terminal amphipathic domain of SP-B by comparing the secondary conformations and surface activities of a family of synthetic peptides based on the native human SP-B sequence, modified by site-specific amino acid substitutions. Circular dichroism measurements show an alpha-helical structure correlating with the ability of the peptides to interact with lipids and with the surface activity of peptide/lipid dispersions. Amino acid substitutions altering either the charge or the hydrophobicity of the residues lowered the helical content and reduced the association of the amino-terminal segment with lipid dispersions. Surface activity of peptide/lipid mixtures was maximally altered by reversal of charge in synthetic peptides. These observations indicate that electrostatic interactions and hydrophobicity are important factors in determining optimal structure and function of surfactant peptides in lipid dispersions.

关键词： PROTEIN SECONDARY structure AMINO ACID SUBSTITUTIONS LIPID-PEPTIDE INTERACTION structure-function relationships OXYGEN DELIVERY

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EVIDENCE FOR INTERNAL SEQUENCE HOMOLOGIES IN LEGUMINOSAE LECTINS - PHYLOGENETICAL IMPLICATIONS

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BIOCHEMICAL SYSTEMATICS AND ECOLOGY 1990年第1期18卷 29-37页

作者： ROUGE, P RISLER, JL CNRS CTR GENET MOLEC F-91198 GIF SUR YVETTE FRANCE

Three stretches of homologous amino acid sequences were recognized along the complete amino acid sequences of two-chain and single-chain Leguminosae lectins. These stretches, of about 28 residues each, were, respectively, located at both ends and in the middle of the polypeptide chain, and exhibited a significant proportion of homologous (20-40%) residues. In addition, they occurred in regions which are essentially buried in nautre and contain a high proportion of .beta.-sheet structures. These findings suggest that genes coding for lectins probably arose by duplication of a common ancestral gene followed by limited divergence. However, as a result of such a common ancestry of Leguminosae lectins, the three-dimensional fold of their polypeptide chains was much better conserved than their constituent amino acids. This could explain why, besides a common structure-function relationship, lectins exhibit different fine sugar specificities.

关键词： Vicieae Leguminosae lectins internal homologies gene duplication structure-function relationships

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THE structure-function relationships OF NITROFLUORENES AND NITROFLUORENONES IN THE SALMONELLA MUTAGENICITY AND CHO SISTER-CHROMATID EXCHANGE ASSAYS

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MUTATION RESEARCH 1988年第3期206卷 367-377页

作者： KITCHIN, RM BECHTOLD, WE BROOKS, AL LOVELACE BIOMED & ENVIRONM RES INST POB 5890 ALBUQUERQUE NM 87185 USA UNIV WYOMING DEPT ZOOL & PHYSIOL LARAMIE WY 82071 USA

Nitrofluorenes and nitrofluorenones are bacterial mutagens and are detected in a variety of environmental pollution sources. We tested a series of nitrosubstituted fluorenes and fluorenones for their genotoxicity using both Salmonella bacteria and Chinese hamster ovary (CHO) cells to determine if structure-function relationships observed in bacteria for mutation induction are similar to those for mutations and SCE induction in mammalian (CHO) cells. The compounds studied were 2-nitrofluorene (2-NF), 2,7-dinitrofluorene (2,7-DNF), 3-nitrofluorenone (3-NFone), 2-nitrofluorenone (2-NFone), 2,7-dinitrofluorenone (2,7-DNFone), 2,4,7-trinitrofluorenone (2,4,7-TNFone), and 2,4,5,7-tetranitrofluorenone (2,4,5,7-TNFone). In bacteria, the presence of carbonyl group to convert mono-nitrofluorenes to nitrofluorenones and the addition of a second nitro group to either mono-nitrofluorene or fluorenone to form the dinitro compounds increased mutagenic activity in the Ames test. Location of the nitro group relative to the carbonyl group was important in enhancing mutagenic activity as 2-nitrofluorenone was more mutagenic than 3-nitrofluorenone. In CHO cells, the di-, tri- and tetra-nitrofluorenones were cytotoxic and delayed the progression of CHO cells through the cell cycle. The degree of the cytotoxicity could be decreased by the addition of S9. None of the compounds produced mutations when tested in the CHO-HGPRT mutation assay with the addition of S9. Nonetheless, the current study did show that these compounds, both with and without the activation by S9, can interact with the DNA and produce SCE in CHO cells. The addition of a carbonyl group had no influence on SCE frequency since both 2-nitrofluorene and 2-nitrofluorenone induced a similar frequency of SCE either with or without S9. Additional nitro groups, forming di, tri- or tetra-nitrofluorenones, increased the frequency of SCE induced, especially when tested with S9 which limits cytotoxicity. The addition of a single nit

关键词： structure-function relationships Nitrofluorenes Nitrofluorenones Sister-chromatid exchange assays CHO Chinese hamster ovary cells SCE

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THE QUANTITATIVE STUDY OF THE ORIENTATION OF COLLAGEN IN COMPACT-BONE SLICES

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BONE 1990年第1期11卷 35-39页

作者： BOYDE, A RIGGS, CM ROYAL VET COLL DEPT SURG & OBSTET HATFIELD HERTS ENGLAND

We describe and validate a simple method for the study of the proportion of collagen fibers (and apatite crystals) in a bone slice parallel with the plane of section. Viewed between crossed circular polarizers, all bone areas with collagen lying more nearly in the plane of section (i.e., transverse [TS] collagen) appear bright whatever its direction in this plane;longitudinal [LS] collagen appears dark, but not as dark as the background. The degree of brightness increases with section thickness, which must therefore be standardized-we chose 100 .mu.m plane parallel sections. We transferred the circularly polarized light [CPL] image via a CCD TV camera to an image analyzing computer. Color-coded maps of the CPL image were used to compare regions within and between sections. The new analytical procedure makes more detailed studies of the fine-structural orientation in compact bone possible, but does this have any significance? To answer this question, a bone in which the in vivo strain pattern had been clearly documented was chosen for particular study. Transverse mid-diaphyseal sections of the equine radius showed a distribution of CPL bright areas which correlated closely with previously reported strain patterns.

关键词： Bone Collagen Circularly polarized light Image analysis structure-function relationships

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SECONDARY structure CHARACTERISTICS OF PROENKEPHALIN PEPTIDE-E, PEPTIDE-B, AND PEPTIDE-F

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NEUROCHEMICAL RESEARCH 1990年第4期15卷 393-399页

作者： HIDDINGA, HJ KATZENSTEIN, GE MIDDAUGH, CR LEWIS, RV UNIV WYOMING DEPT MOLEC BIOL BOX 3944 UNIV STN LARAMIE WY 82071 USA

The conformations of three adrenal medullary enkephalin containing polypeptides (ECPs) were investigated to gain an understanding of their potential structure-activity relationships. Secondary structure characteristics of peptides E, B, and F were examined by circular dichroism (CD) under conditions designed to mimic both the soluble state and the anisotropic environment which exists at the biological effector site. Conformational differences between the three peptides were further examined by Fourier Treansform Infrared Spectroscopy (FTIR) and by empirical predictions for conformation and hydrophobic periodicity. Although all three peptides have a similar structure, existing in random configurations in aqueous solutions, they do exhibit unique individual potentials to assume secondary structure in less polar environments. These conformational differences may be important factors in determining their unique individual biological activities.

关键词： conformation enkephalin containing polypeptide Opioid peptide structure-function relationships

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RIBULOSE BISPHOSPHATE CARBOXYLASE IN ALGAE - SYNTHESIS, ENZYMOLOGY AND EVOLUTION

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PHOTOSYNTHESIS RESEARCH 1990年第2期26卷 69-85页

作者： NEWMAN, SM CATTOLICO, RA UNIV WASHINGTON DEPT BOT SEATTLE WA 98195 USA

Studies demonstrating differences in chloroplast structure and biochemistry have been used to formulate hypotheses concerning the origin of algal plastids. Genetic and biochemical experiments indicate that significant variation occurs in ribulose-1,5-bisphosphate carboxylase (Rubisco) when supertaxa of eukaryotic algae are compared. These differences include variations in the organelle location of the genes and their arrangement, mechanism of Rubisco synthesis, polypeptide immunological reactivity and sequence, as well as efficacy of substrate (ribulose bisphosphate and CO2) binding and inhibitor (6-phosphogluconate) action. The structure-function relationships observed among chromophytic, rhodophytic, chlorophytic and prokaryotic Rubisco demonstrate that: (a) similarities among chromophytic and rhodophytic Rubisco exist in substrate/inhibitor binding and polypeptide sequence, (b) characteristic differences in enzyme kinetics and subunit polypeptide structure occur among chlorophytes, prokaryotes and chromophytes/rhodophytes, and (c) there is structural variability among chlorophytic plant small subunit polypeptides, in contrast to the conservation of this polypeptide in chromophytes and rhodophytes. Taxa-specific differences among algal Rubisco enzymes most likely reflect the evolutionary history of the plastid, the functional requirements of each polypeptide, and the consequences of encoding the large and small subunit genes in the same or different organelles.

关键词： endosymbiont eukaryotic algae Rubisco structure-function relationships

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SEA-SNAKE (MICROCEPHALOPHIS-GRACILIS) HEMOGLOBIN - PRIMARY structure AND relationships TO OTHER FORMS

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JOURNAL OF PROTEIN CHEMISTRY 1990年第5期9卷 533-541页

作者： ISLAM, A PERSSON, B ZAIDI, ZH JORNVALL, H KAROLINSKA INST DEPT CHEM 1 S-10401 STOCKHOLM 60 SWEDEN HUDDINGE UNIV HOSP CTR BIOTECHNOL S-14186 HUDDINGE SWEDEN UNIV KARACHI HEJ RES INST CHEM KARACHI 32 PAKISTAN

The hemoglobin of the sea snake Microcephalophis gracilis was purified and the primary structure of the alpha and beta-chains determined. This is the first sea snake hemoglobin structure characterized, and apparently also the first complete structure of any snake hemoglobin (an alpha-chain of a viper was known), allowing judgments of reptilian variants. Variations between the sea snake form and other reptilian forms are large (52-65 differences for the alpha-chains), of similar order as those between the sea snake and avian (56-65 differences) or human (58 differences) forms. functionally, 19 residues at alpha/beta-contact areas and 7 at heme contacts are exchanged in relation to the human alpha and beta-chains. Four positions of the sea snake hemoglobin contain residues thus far unique to this form. However, all replacements appear compatible with conserved overall functional properties.

关键词： HEMOGLOBIN SEA SNAKE AMINO ACID SEQUENCE structure-function relationships REPTILE relationships

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AN INSULIN-LIKE HYBRID CONSISTING OF A MODIFIED A-DOMAIN OF HUMAN INSULIN-LIKE GROWTH FACTOR-I AND THE B-CHAIN OF INSULIN

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JOURNAL OF PROTEIN CHEMISTRY 1990年第4期9卷 389-395页

作者： ZONG, L BURKE, GT KATSOYANNIS, PG CUNY MT SINAI SCH MED DEPT BIOCHEM BOX 1020 1 GUSTAVE L LEVY PL NEW YORK NY 10029 USA

We have synthesized an insulin-like compound, consisting of the B-chain of bovine insulin and an A-chain corresponding to the A-domain of human insulin-like growth factor-I (IGF-I), in which the isoleucine residue normally present in position 2 of the A-domain of IGF-I has been replaced with glycine. Biological evaluation of the compound indicated that its insulin like activity (insulin receptor-binding and stimulation of lipogenesis) was 0.2%, and its growth-factor activity (stimulation of thymidine incorporation) was less than 1%, both relative to natural insulin. We conclude that interactions between IleA2 and TyrA19, which are crucial to high biological activity in insulin, are also present in IGF-I, and are equally critical for its biological activity.

关键词： growth-promoting activity IGF-I/insulin hybrid insulin activity structure-function relationships

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