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PubMed1982

Candidiasis in captive cetaceans.

Disseminated Candida albicans infections were found or suspected in 4 captive cetaceans. Ketoconazole at a dosage of 2.5 mg/kg, BID, administered orally for 18 days, followed by 8 biweekly oral doses of levamisole hydrochloride at the rate of 9 mg/kg, resulted in regression of clinical signs of candidiasis in an adult male Atlantic bottlenose dolphin (Tursiops truncatus). A higher dosage of ketoconazole (6 mg/kg, BID) was effective in eliminating the shedding of C albicans from an adult male belukha whale (Delphinapterus leucas). A juvenile female harbor porpoise (Phocoena phocoena) treated with nystatin died with disseminated candidiasis, as did a juvenile male longfinned pilot whale (Globicephala melaena) treated with nystatin and levamisole. Three other adult bottlenose dolphins, a juvenile female belukha whale, and a female Commerson's dolphin (Cephalorhynchus commersonii) kept in the same water system never had evidence of candidiasis. A 5th bottlenose dolphin (an adult female) was culture-positive on 1 occasion, but never had signs of the disease.

Animals↗
PubMed1995

[Study of squirrel myoglobin. Oxidation-reduction reaction between squirrel oxymyoglobin and ferricytochrome c].

Metmyoglobin (met-Mb) of Yakutian ground squirrel (Citellus undulatus) was isolated from skeletal muscles and fractionated using gel and ion-exchange chromatography. An electrophoretically homogeneous major fraction of met-Mb (pI 7.05) was obtained with a 90% yield. The rates of the redox reaction between ground squirrel oxy-Mb and horse and ground squirrel ferri-Cyt c were studied in the pH range of 5-8 at ionic strengths ranging from 0.01 to 1. The experimental results were compared to the earlier obtained data for sperm whale and pig Mbs whose three-dimensional structures and physico-chemical properties are well studied. It was shown that the properties of ground squirrel Mb are very similar to those of pig Mb but differ from those of whale Mb. The amino acid sequences of about 50 Mbs from various mammals as well as from some avian and chordate species (Protein Data Bank) were compared. It was found that rodent myoglobins can be divided into two distinct groups. Myoglobins of animals living in water are identical with those of sperm whale and other cetaceans, while myoglobins of ground rodents closely resemble pig Mb. The number of non-homologous amino acid substitutes in each of the two groups (1-2 positions) is much less compared to all rodent myoglobins (8 positions). The charge structure of the Mb contact site interacting with Cyt c in the course of the electron transfer reaction is strictly conservative for all mammalian Mbs tested in this study (but not for birds and chordates). It is assumed that under certain extreme conditions oxy-Mb can directly interact with cell organelles, such as mitochondria.

Animals↗
PubMed2005

Identification, quantification, and synthesis of a novel dimethoxylated polybrominated biphenyl in marine mammals caught off the coast of Japan.

Bioaccumulation of persistent organic compounds can eventually lead to concentrations in wildlife and humans that are deleterious to health. The present paper documents the identification, quantification, and synthesis of a novel compound, 2,2'-dimethoxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diMeO-BB80), present in the marine mammals Striped dolphin (Stenella coeruleoalba), Bottlenose dolphin (Tursiops truncatus), Minke whale (Balaenoptera acutorostrata), and Baird's beaked whale (Berardius bairdii) caught in the Pacific Ocean. Identification was based on comparison of the relative retention times of the compound on two gas chromatographic columns of different polarities to those of an authentic standard. Furthermore, this identification was also supported by comparison of the full scan mass spectrometric data collected employing electron ionization (El), positive ion chemical ionization (PICI), and electron capture negative ionization (ECNI). The concentrations of 2,2'-diMeO-BB80 in the samples ranged from 12 to 800 ng/g lipid, making this consistently one of the most abundant compounds among those analyzed, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and methoxylated PBDEs. The known occurrence of 3,3',5,5'-tetrabromo-2,2'-biphenyldiol (2,2'-diOH-BB80) in the marine environment as a natural product suggests that its methylated derivative, 2,2'-diMeO-BB80, is also of natural origin. To obtain the necessary authentic standards, synthesis was performed of 2,2'-diMeO-BB80 and the known natural product 2',6-dimethoxy-2,3',4,5'-tetrabromodiphenyl ether (2',6-diMeO-BDE68).

Animals↗
PubMed1996

Functional morphology and homology in the odontocete nasal complex: implications for sound generation.

The site and physiologic mechanism(s) responsible for the generation of odontocete biosonar signals have eluded investigators for decades. To address these issues we subjected postmortem toothed whale heads to interrogation using medical imaging techniques. Most of the 40 specimens (from 19 species) were examined using x-ray computed tomography (CT) and/or magnetic resonance imaging (MR). Interpretation of scan images was aided by subsequent dissection of the specimens or, in one case, by cryosectioning. In all specimens we described a similar tissue complex and identified it as the hypothetical biosonar signal generator. This complex includes a small pair of fatty bursae embedded in a pair of connective tissue lips, a cartilaginous blade, a stout ligament, and an array of soft tissue air sacs. Comparing and contrasting the morphologic patterns of nasal structures across species representing every extant odontocete superfamily reveals probable homologous relationships, which suggests that all toothed whales may be making their biosonar signals by a similar mechanism.

Animals↗
PubMed2003

Tryptophanyl substitutions in apomyoglobin affect conformation and dynamic properties of AGH subdomain.

The solvent accessibilities to the tryptophanyl microenvironments of wild type sperm whale apomyoglobin (apoMb) and two mutants (W7F and W14F) containing a single tryptophan are measured by fluorescence quenching studies. The results are compared to those relative to horse apoMb. In the wild type sperm whale protein, no difference is noticed in the solvent accessibility of the two indole residues, as documented by the values of the Stern-Volmer constants. By contrast, the two tryptophan residues of horse apoMb are exposed to the solvent in a different way, thus indicating that some local conformational differences exist between the two homologous proteins in solution. The single W --> F substitution at either position 7 or 14 determines local conformational changes that increase the accessibility of the remaining indole residue but do not affect the overall architecture of the protein molecule.

Acrylamide↗
PubMed1993

Matrix-assisted laser desorption of peptides and proteins on a quadrupole ion trap mass spectrometer.

The use of ultraviolet matrix-assisted laser desorption (MALD) to ionize peptides and proteins for analysis in a quadrupole ion trap is described. An ion source was modified to accommodate a fiber optic to transmit laser radiation from a nitrogen laser (337 nm) to the tip of the sample probe containing peptide or protein samples in a matrix of 2,5-dihydroxybenzoic acid (DHB) or 3,4-dimethoxy-4-hydroxy-cinnamic acid. Detection limits are demonstrated with 10 fmol of sperm-whale myoglobin. The dimer of sperm-whale myoglobin was also observed at m/z 34,430. A comparison is made of the tandem mass spectrum of (MS/MS) of human angiotensin I desorbed by MALD to that of the peptide desorbed by liquid secondary-ion mass spectrometry. Both spectra were found to contain abundant structural information.

Angiotensin I↗
PubMed1996

Bioaccumulation of vanadium and other trace metals in livers of Alaskan cetaceans and pinnipeds.

Concentrations for 38 elements are routinely measured in the marine mammal liver tissues archived in the National Biomonitoring Specimen Bank (NBSB). Results show that hepatic concentrations of vanadium, selenium, silver, cadmium, and mercury are positively correlated with age for beluga whales (Delphinapterus leucas) and of vanadium, selenium, cadmium, and mercury with length for ringed seals (Phoca hispada). Many researchers have reported linear correlations of hepatic selenium, cadmium, and mercury with marine mammal age; however, there is only one other report of a linear correlation of hepatic vanadium with marine mammal age. Vanadium levels are at or below detection limits (< or = 0.01 micrograms/g) in liver tissues of U.S. east coast marine mammals from the NBSB but are present at levels ranging from 0.02 to 1.2 micrograms/g of wet weight in the tissues of Alaskan marine mammals. Although only three bearded seal (Eriganthus barbatus) and three bow-head whale (Balaena mysticetus) liver samples have been analyzed, hepatic vanadium levels also increased with animal size for these species. The presence of relatively high levels of vanadium in the livers of these Alaskan animals may reflect a unique dietary source of vanadium, a unique geochemical source of vanadium, or anthropogenic input to the Alaskan marine environment.

Aging↗
PubMed1989

Comparative oxygen affinity of fish and mammalian myoglobins.

Myoglobins from rat, coho salmon (Oncorhynchus kisutch), buffalo sculpin (Enophrys bison) hearts, and yellowfin tuna (Thunnus albacares) red skeletal muscle were partially purified and their O2 binding affinities determined. Commercially prepared sperm whale myoglobin was employed as an internal standard. Tested at 20 degrees C, myoglobins from salmon and sculpin bound O2 with lower affinity than myoglobins from the rat or sperm whale. Oxygen binding studies at 12 degrees C and 37 degrees C suggest that this difference is adaptive, permitting myoglobins from cold-adapted fish to function at physiologically relevant temperatures. Taken together, purification and O2 binding data obtained in this study reveal a previously unrecognized diversity of myoglobin structure and function.

Animals↗
PubMed1992

Effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 94-100 (antigenic site 3) of myoglobin.

Amino acid substitutions outside protein antigenic sites are very frequently assumed to exert no effect on binding to antiprotein antibodies, especially if these are monoclonal antibodies (mAbs). In fact, a very popular method for localization of residues in protein antigenic sites is based on the interpretation that whenever a replacement causes a change in binding to antibody, then that residue will be located in the antigenic site. To test this assumption, mAbs of predetermined specificity were prepared by immunization with a free (i.e., without coupling to any carrier) synthetic peptide representing region 94-100 of sperm whale myoglobin (Mb). The cross-reactivities and relative affinities of three mAbs with eight Mb variants were studied. Five Mb variants which had no substitutions within the boundaries of the designed antigenic site exhibited remarkable, and in two cases almost complete, loss in cross-reactivity relative to the reference antigen, sperm whale Mb. Two myoglobins, each of which had one substitution within region 94-100, showed little or no reactivity with the three mAbs. It is concluded that substitutions outside an antigenic site can exert drastic effects on the reactivity of a protein with mAbs against the site and that caution should be exercised in interpreting cross-reactivity data of proteins to implicate residues directly in an antigenic site.

Amino Acid Sequence↗
PubMed1992

Effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 15-22 (antigenic site 1) of myoglobin.

Monoclonal antibodies (mAbs) of predetermined specificity were prepared by immunizing with a free (i.e., not conjugated to any carrier) synthetic peptide representing region 15-22 (site 1) of sperm whale myoglobin (SpMb). The cross-reactions of Mb variants with three mAbs were studied in order to determine whether such interactions are influenced by substitutions outside the site. Finback whale Mb, which has no substitutions within region 15-22, showed lower cross-reactivity and relative binding affinity than the reference antigen, SpMb. Bottle-nose Atlantic dolphin myoglobin (BdMb) and badger myoglobin (BgMb), although they have identical substitutions within region 15-22 (Ala-15 to Gly and Val-21 to Leu), showed very different binding properties. The cross-reaction of BdMb was quite comparable to that of SpMb, while that of BgMb was much lower. Since the two proteins have identical structures in regions 15-22, the differences in their cross-reactivities are readily attributed to the effects of substitutions outside this region. Another pair of myoglobins, horse myoglobins (HsMb) and chicken myoglobin (ChMb), also have two identical substitutions (Ala-15 to Gly and Val-21 to Ile) within region 15-22, but possessed different cross-reactivity. The results indicate that the reaction of mAbs, whose specificity is precisely known and predetermined by the immunizing free peptide, can be markedly affected by substitutions outside the indicated binding region on the protein.

Amino Acid Sequence↗
PubMed1992

Effects of amino acid substitutions outside an antigenic site on protein binding to monoclonal antibodies of predetermined specificity obtained by peptide immunization: demonstration with region 56-62 (antigenic site 2) of myoglobin.

This work was carried out in order to study the effects of substitutions outside antigenic site 2 of sperm whale myoglobin (SpMb) on the reactivity of protein variants with antisite 2 monoclonal antibodies (mAbs). A synthetic peptide corresponding to region 56-62 (site 2) of SpMb was used as an immunogen in mice in its free form (i.e., without coupling to any carrier) to prepare a panel of mAbs whose predetermined specificity is directed, by design, against this region. The binding of three of these mAbs to eight Mbs from different species was studied. Myoglobins of Pacific common dolphin, finback whale, and horse, which have no substitutions within region 56-62 relative to SpMb, showed remarkable differences in their cross-reactivities and relative affinities with each of the mAbs. Myoglobins of badger, chicken, and dog, although they have an identical substitution within the site (Ala-57 to Gly), exhibited cross-reactivities with a given mAb that were affected differently. Echidna Mb, which has one replacement (Glu-59 to Ala) within region 56-62, displayed greatly reduced cross-reactivities and relative binding affinities. The results, especially those from Mbs that have no substitutions within the boundaries of site 2, clearly indicate that substitutions outside site 2 of Mb can exert drastic effects on the binding of the Mb variants with mAbs whose specificity was predesigned to be against the site. These indirect effects and their impact on site reactivity will completely explain previous findings on cross-reactivities of Mb variants with mAbs of unknown specificity and will rule out the postulations of discontinuous sites in Mb, which were based on the assumption that every substitution affecting reactivity is directly involved in binding to antibody.

Amino Acid Sequence↗
PubMed1993

Binding affinity of influenza virus N9 neuraminidase with Fab fragments of monoclonal antibodies NC10 and NC41.

Sedimentation equilibrium centrifugation has been applied to determine the affinity and stoichiometry of the interaction between Fab fragments, derived from monoclonal antibodies NC10 and NC41, with influenza virus neuraminidase N9 isolated from either tern or whale. Although the two neuraminidase epitopes recognized by NC10 and NC41 Fab overlap, crystallographic studies have shown that the modes of binding of each Fab are different. The sedimentation equilibrium experiments described here reveal that the binding affinities are also different, with NC10 Fab binding more strongly to each neuraminidase. Furthermore, comparison of the affinity of binding of each antibody fragment reveals a stronger interaction with tern neuraminidase than with whale neuraminidase. Although the respective epitopes recognized by each antibody on the two antigens are similar, this technique shows that they do nevertheless possess sufficient differences to affect significantly the binding of antibody.

Animals↗
PubMed2000

Solution 1H NMR investigation of the seating and rotational "hopping" of centrosymmetric etioheme-I in myoglobin: effect of globin origin and its oxidation/spin state on heme dynamics.

Solution 1H NMR spectroscopy was used to investigate the heme active-site structure and dynamics of rotation about the Fe-His bond of centrosymmetric etioheme-I reconstituted into sperm whale and horse myoglobin (Mb). Comparison of the NOESY cross-peak pattern and paramagnetic relaxation properties of the cyanomet complexes confirm a heme pocket that is essentially the same as Mb with either native protoheme or etioheme-I. Dipolar contacts between etioheme and the conserved heme pocket residues establish a unique seating of etioheme that conserves the orientation of the N-Fe-N vector relative to the axial His plane, with ethyl groups occupying the vinyl positions of protoheme. Saturation transfer between methyls on adjacent pyrroles in etioheme-reconstituted horse Mb in all accessible oxidation/spin states reveals rotational hopping rates that decrease dramatically with either loss of ligands or reduction of the heme, and correlate qualitatively with expectations based on the Fe-His bond strength and the rate of heme dissociation from Mb. The rate of hopping for etioheme in metMbCN, in contrast to hemes with propionates, is the same in the sperm whale and horse proteins.

Animals↗
PubMed1991

Control and recognition of anionic ligands in myoglobin.

Equilibrium and kinetic experiments on site-directed mutants of a synthetic sperm whale myoglobin (Mb) gene have been performed. Results on the reactivity on both ferric and ferrous wild type and mutants Mb's are presented. Analysis of ligand binding to His (E7) Val and His (E7) Val-Thr (E10) Arg mutants compared to wild-type sperm whale, horse and Aplysia limacina Mb's, shows that the introduction of an arginyl residue at the topological position E10 greatly enhances the stability of the various Mg:heme ligand adducts. Alternative mechanisms of ligand stabilization may therefore be operative in Mb's lacking the distal histidine.

Animals↗
PubMed1990

Organic mercury in Greenland birds and mammals.

Muscle, liver and kidney samples of 20 species of birds, seals, whales and polar bear were analyzed for total and organic mercury. Organic mercury concentrations varied considerably between individuals. A general tendency towards age accumulation was found, together with log-linear correlations between organic mercury concentrations in the three tissues. The major part of the muscle mercury was organic (maximum concentration found was 1235 micrograms kg-1 wet wt). This also applied to liver of birds, while in mammal liver organic mercury concentrations approached a level of 2000 micrograms kg-1 wet wt, which was not exceeded even when the total mercury concentration was greater than 100,000 micrograms kg-1 wet wt. The percentage of organic mercury in relation to total mercury in kidney of seals and whales was 10-20% (maximum 982 micrograms organic mercury kg-1 wet wt), while in polar bear it was less than 6% (maximum 217 micrograms kg-1 wet wt). For the monitoring of local food in the Arctic, the simpler and less expensive analysis of total mercury suffices when testing muscle, whereas liver and kidney should be tested for organic mercury as well.

Animals↗
PubMed1986

The antibody response to myoglobin--I. Systematic synthesis of myoglobin peptides reveals location and substructure of species-dependent continuous antigenic determinants.

Sets of peptides representing all the possible hepta-, octa-, nona- and decapeptides of sperm whale myoglobin were synthesized. An ELISA method was used to detect the ability of antibodies, present in antisera raised against native sperm whale myoglobin, to bind to these peptides. Antisera made in two species were compared. It was found that the peptides recognized by the antibodies were a function of the species in which the antiserum was prepared and of the individual outbred member of that species. Peptides corresponding to surface epitopes of the native antigen were identified by reacting the antisera with native antigen prior to ELISA testing on peptides. More detailed analysis of one epitope revealed that, for some sera, a leucine residue which is facing inwards in the crystal structure is critical for the binding of antibody to the peptide. This suggests that binding between native antigen and antibody can require a restructuring of the native antigen.

Animals↗
PubMed1987

Dynamic aspects of the heme-binding site in phylogenetically distant myoglobins.

Dynamic aspects of the heme-binding site of myoglobins derived from two phylogenetically distant species, namely sperm whale and bluefin tuna, have been investigated by studying steady-state and time-resolved emission properties of 2-p-toluidinyl-6-naphthalene sulfonic acid (TNS) apomyoglobin conjugates. Multi-frequency phase and modulation fluorometry data indicate that charge movements occur in the fluorophore environment during the excited state lifetime in the sperm whale myoglobin system. In the case of the bluefin tuna myoglobin TNS adduct these movements were not detected, indicating that the relaxation processes differ in the two types of myoglobins.

Animals↗
PubMed1996

Iron ligand recognition by monomeric hemoglobins.

Binding affinities of monomeric Glycera dibranchiata hemoglobin for some anions and heterocyclic amines, including imidazoles, pyrazole, triazole and tetrazole have been evaluated and compared with those of sperm whale and horse heart myoglobin. The proteins' affinities for substituted heterocyclic amines are strongly influenced by the steric bulk and flexibility of the aromatic ring. The ligand coordination mode depends on the heme oxidation state, iron(III) amine adducts being more stable than the iron(II) adducts, the higher affinities of stronger Brønsted-Lowry bases reflecting their essentially sigma-donor character. The bifunctional molecule morpholinoethylisocyanide acts as a redox-state-dependent ambidentate ligand, binding as an N-donor to iron(III), but as a C-donor to iron(II). pH-Dependences of the ESR and optical spectra of the azole adducts reveal iron-linked ionisations and spin-equilibria in the heme pocket. Enthalpy and entropy changes for the binding process were estimated for several ligands, and mutually compensatory behaviour is observed globally for delta H degree and delta S degree. At the compensation temperature theta, the binding affinities of monomeric Glycera dibranchiata hemoglobin and sperm whale myoglobin are similar and associated with free energy changes delta G degree (theta) approximately -9 +/- 1 kJ mol-1 for the heterocyclic and anionic ligands.

Animals↗