| retroposon analysis of major cetacean lineages: the monophyly of toothed whales and the paraphyly of river dolphins. | sine (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (odontoceti), especially river dolphins. here, we characterize 25 informative sines inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these sine loci to estimate divergence times among lineages. we demonstrate that: (i) odontocetes are monophyletic; (ii) ... | 2001 | 11416211 |
| quantifying the energy stores of capital breeding humpback whales and income breeding sperm whales using historical whaling records. | cetacean energy stores are known to vary according to life history, reproductive status and time of year; however, the opportunity to quantify these relationships is rare. using a unique set of historical whaling records from western australia (1952-1963), we investigated energy stores of large cetaceans with differing life histories, and quantified the relationship between total body lipid and length for humpback whales (megaptera novaeangliae) (n = 905) and sperm whales (physeter macrocephalus ... | 2017 | 28405350 |
| bony outgrowths on the jaws of an extinct sperm whale support macroraptorial feeding in several stem physeteroids. | several extinct sperm whales (stem physeteroidea) were recently proposed to differ markedly in their feeding ecology from the suction-feeding modern sperm whales kogia and physeter. based on cranial, mandibular, and dental morphology, these miocene forms were tentatively identified as macroraptorial feeders, able to consume proportionally large prey using their massive teeth and robust jaws. however, until now, no corroborating evidence for the use of teeth during predation was available. we rep ... | 2014 | 24821119 |
| evolution of the mhc-dqb exon 2 in marine and terrestrial mammals. | on the basis of a general low polymorphism, several studies suggest that balancing selection in the class ii major histocompatibility complex (mhc) is weaker in marine mammals as compared with terrestrial mammals. we investigated such differential selection among cetacea, artiodactyla, and primates at exon 2 of mhc-dqb gene by contrasting indicators of molecular evolution such as occurrence of transpecific polymorphisms, patterns of phylogenetic branch lengths by codon position, rates of nonsyno ... | 2013 | 23064401 |
| microvascular patterns in the blubber of shallow and deep diving odontocetes. | blubber, a specialized form of subdermal adipose tissue, surrounds marine mammal bodies. typically, adipose tissue is perfused by capillaries but information on blubber vascularization is lacking. this study's goals were to: 1) describe and compare the microvasculature (capillaries, microarterioles, and microvenules) of blubber across odontocete species; 2) compare microvasculature of blubber to adipose tissue; and 3) examine relationships between blubber's lipid composition and its microvascula ... | 2012 | 22592863 |
| endobronchial sand casts: an unusual marker of saltwater immersion in a juvenile pygmy sperm whale (kogia breviceps). | | 2011 | 20853180 |
| lung size and thoracic morphology in shallow- and deep-diving cetaceans. | shallow-diving, coastal bottlenose dolphins (tursiops truncatus) and deep-diving, pelagic pygmy and dwarf sperm whales (kogia breviceps and k. sima) will experience vastly different ambient pressures at depth, which will influence the volume of air within their lungs and potentially the degree of thoracic collapse they experience. this study tested the hypotheses that lung size will be reduced and/or thoracic mobility will be enhanced in deeper divers. lung mass (t. truncatus, n = 106; kogiids, ... | 2010 | 20077515 |
| predation by killer whales (orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes. | a disparate selection of toothed whales (odontoceti) share striking features of their acoustic repertoires including the absence of whistles and high frequency but weak (low peak-to-peak source level) clicks that have a relatively long duration and a narrow bandwidth. the non-whistling, high frequency click species include members of the family phocoenidae, members of one genus of delphinids, cephalorhynchus, the pygmy sperm whale, kogia breviceps, and apparently the sole member of the family po ... | 2007 | 17584238 |
| a functional comparison of the hyolingual complex in pygmy and dwarf sperm whales (kogia breviceps and k. sima), and bottlenose dolphins (tursiops truncatus). | the function of the hyolingual complex in three odontocete species was investigated to compare adaptations of divergent feeding strategies, suction and ram feeding. pygmy and dwarf sperm whales, members of the genus kogia (or kogiids), are known to be strong suction feeders. we tested the hypotheses that kogiids would have a larger, more robust hyolingual complex, and that hyolingual muscles would have a greater maximum theoretical muscle tension compared with ram-based feeders such as bottlenos ... | 2007 | 17555545 |
| magnetic resonance imaging and computed tomography as tools for the investigation of sperm whale (physeter macrocephalus) teeth and eye. | scanning techniques such as magnetic resonance imaging (mri) and computed tomography (ct) are useful tools in veterinary and human medicine. here we demonstrate the usefulness of these techniques in the study of the anatomy of wild marine mammals as part of a necropsy. mri and ct scans of sperm whale teeth (n = 4) were performed. the methods were compared and further compared to current standard methods for evaluation of tooth layering. for mri a zero echo time sequence was used, as previously d ... | 2017 | 28606113 |
| intermediate states of apomyoglobin: are they parts of the same area of conformations diagram? | several research teams have reported detection and characterization of various apomyoglobin intermediate states different in their accumulation mode, thus putting a natural question as to proportions of these intermediates. the current report presents spectral properties of sperm whale apomyoglobin studied over a wide range of conditions with the use of circular dichroism and fluorescence techniques. based on the experimental data, a diagram of apomyoglobin conformational states has been constru ... | 2017 | 28601072 |
| feeding kinematics of kogia and tursiops (odontoceti: cetacea): characterization of suction and ram feeding. | the feeding kinematics of dwarf and pygmy sperm whales (kogia sima and k. breviceps) and bottlenose dolphins tursiops truncatus were characterized and compared incorporating the ram-suction index (rsi). mean rsi data support a suction feeding strategy for kogia (-0.67+/-0.29; mean +/- s.d.) and a ram feeding strategy for tursiops (0.94+/-0.11; mean +/- s.d.). tursiops displayed two ram-based feeding behaviours: open gape approach, where gape was at least 50% of maximum in the first video field, ... | 2005 | 16169949 |
| killer whale (orcinus orca) whistles from the western south atlantic ocean include high frequency signals. | acoustic parameters of killer whale (orcinus orca) whistles were described for the western south atlantic ocean and highlight the occurrence of high frequency whistles. killer whale signals were recorded on december of 2012, when a pod of four individuals was observed harassing a group of sperm whales. the high frequency whistles were highly stereotyped and were modulated mostly at ultrasonic frequencies. compared to other contour types, the high frequency whistles are characterized by higher ba ... | 2015 | 26428807 |
| sperm whales and killer whales with the largest brains of all toothed whales show extreme differences in cerebellum. | among cetaceans, killer whales and sperm whales have the widest distribution in the world's oceans. both species use echolocation, are long-lived, and have the longest periods of gestation among whales. sperm whales dive much deeper and much longer than killer whales. it has long been thought that sperm whales have the largest brains of all living things, but our brain mass evidence, from published sources and our own specimens, shows that big males of these two species share this distinction. d ... | 2014 | 24852603 |
| stepwise sequence determination from the carboxyl terminus of peptides. | the thiocyanate method for stepwise degradation of peptides from their cooh termini [stark, g. r. (1968) biochemistry 7, 1796] has been investigated. the method involves first the reaction of the cooh-terminal residue with thiocyanate in an activation solvent of acetic acid and acetic anhydride and then cleavage of the cooh-terminal residue as its 2-thiohydantoin by acetohydroxamate in aqueous solution. the two steps of the degradation have been studied by using model peptides, and conditions ha ... | 1982 | 7138804 |
| sperm whale long-range echolocation sounds revealed by antares, a deep-sea neutrino telescope. | despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the mediterranean sea, unlike other regions of the world, the species population status is still presently uncertain. the analysis of two years of continuous acoustic data provided by the antares neutrino telescope revealed the year-round presence of sperm whales in the ligurian sea, probably associated with the availability of cephalopods in the region. the presence of the ligurian sea sperm ... | 2017 | 28401960 |
| karyotypes and idiograms of sperm and pygmy sperm whales. | | 1973 | 4778107 |
| a survey of trace element distribution in tissues of the dwarf sperm whale (kogia sima) stranded along the south carolina coast from 1990-2011. | few studies report trace elements in dwarf sperm whale (kogia sima). as high trophic level predators, marine mammals are exposed through diet to environmental contaminants including metals from anthropogenic sources. inputs of hg, pb, and cd are of particular concern due to toxicity and potential for atmospheric dispersion and subsequent biomagnification. liver and kidney tissues of stranded k. sima from coastal south carolina, usa, were analyzed for 22 trace elements. age-related correlations w ... | 2015 | 26386505 |
| a versatile system for high-throughput in situ x-ray screening and data collection of soluble and membrane-protein crystals. | in recent years, in situ data collection has been a major focus of progress in protein crystallography. here, we introduce the mylar in situ method using mylar-based sandwich plates that are inexpensive, easy to make and handle, and show significantly less background scattering than other setups. a variety of cognate holders for patches of mylar in situ sandwich films corresponding to one or more wells makes the method robust and versatile, allows for storage and shipping of entire wells, and en ... | 2016 | 28261000 |
| responses of male sperm whales (physeter macrocephalus) to killer whale sounds: implications for anti-predator strategies. | interactions between individuals of different cetacean species are often observed in the wild. killer whales (orcinus orca) can be potential predators of many other cetaceans, and the interception of their vocalizations by unintended cetacean receivers may trigger anti-predator behavior that could mediate predator-prey interactions. we explored the anti-predator behaviour of five typically-solitary male sperm whales (physeter macrocephalus) in the norwegian sea by playing sounds of mammal-feedin ... | 2013 | 23545484 |
| estimated tissue and blood n(2) levels and risk of decompression sickness in deep-, intermediate-, and shallow-diving toothed whales during exposure to naval sonar. | naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue n(2) gas bubbles. increased tissue and blood n(2) levels, and thereby increased risk of decompression sickness (dcs), is thought to result from changes in behavior or physiological responses during diving. previous theoretical studies have used hypothetical sonar-induced changes in both behavior and physiology to model blood and tissue n(2) tension [formula: see text], but this is the first ... | 2012 | 22590458 |
| cetacean acoustic detections from free-floating vertical hydrophone arrays in the southern california current. | drifting acoustic recorders were deployed in the southern california current during fall 2014. two hydrophones configured as a 2-m vertical array at 100 m depth recorded using a 192 khz sample rate on a 10% duty cycle (2 min/20 min). beaked whales were detected in 33 of 8618 two-minute recordings. sperm whales were detected in 185 recordings, and dolphins in 2291 recordings. many beaked whales detected were over an abyssal plain and not associated with slope or seamount features. results show th ... | 2016 | 27908036 |
| the giant bite of a new raptorial sperm whale from the miocene epoch of peru. | the modern giant sperm whale physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller miocene sperm whales (physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale orcinus orca. whereas very large physeteroid teeth have been discovered in various miocene localities, associated diagnostic ... | 2010 | 20596020 |
| a comparative study on ceramide composition of cetacean brain gangliosides. | 1. ceramide composition and n-glycolylneuraminic acid content of gangliosides from gray and white matters and myelin of cerebrum and cerebellum were analyzed in eight species belonging to the suborder odontoceti and two species to mystacoceti. 2. the most characteristic feature was high contents of c20:0 (10-40%) and c24 species (5-40%). 3. content of hydroxy fatty acid of c24 species was higher in cerebellum (5-20%) than cerebrum (0-3%). 4. major component of long-chain base was dc18:1 (70-90%) ... | 1992 | 1458845 |
| gene-culture coevolution in whales and dolphins. | whales and dolphins (cetacea) have excellent social learning skills as well as a long and strong mother-calf bond. these features produce stable cultures, and, in some species, sympatric groups with different cultures. there is evidence and speculation that this cultural transmission of behavior has affected gene distributions. culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. there are ecotype-specific signals of selection in functi ... | 2017 | 28739936 |
| vertebral bone microarchitecture and osteocyte characteristics of three toothed whale species with varying diving behaviour. | although vertebral bone microarchitecture has been studied in various tetrapods, limited quantitative data are available on the structural and compositional changes of vertebrae in marine mammals. whales exhibit exceptional swimming and diving behaviour, and they may not be immune to diving-associated bone pathologies. lumbar vertebral bodies were analysed in three toothed whale species: the sperm whale (physeter macrocephalus), orca (orcinus orca) and harbour porpoise (phocoena phocoena). the b ... | 2017 | 28487524 |
| the myoglobin of the killer whale (orcinus orca). | whereas the myoglobin of the dolphin surprisingly resembles that of the sperm whale more than that of the porpoise, the myoglobin of a killer whale does not show this feature. it differs from the myoglobins of the dolphin in 6, of the porpoise in 8, and of the sperm whale in 14 positions. the residues in which the cetaceans differ are localised in one particular area of the molecule. | 1977 | 849459 |
| mitogenomic analyses provide new insights into cetacean origin and evolution. | the evolution of the order cetacea (whales, dolphins, porpoises) has, for a long time, attracted the attention of evolutionary biologists. here we examine cetacean phylogenetic relationships on the basis of analyses of complete mitochondrial genomes that represent all extant cetacean families. the results suggest that the ancestors of recent cetaceans had an explosive evolutionary radiation 30-35 million years before present. during this period, extant cetaceans divided into the two primary grou ... | 2004 | 15177677 |
| biocatalytic synthesis of allylic and allenyl sulfides through a myoglobin-catalyzed doyle-kirmse reaction. | the first example of a biocatalytic [2,3]-sigmatropic rearrangement reaction involving allylic sulfides and diazo reagents (doyle-kirmse reaction) is reported. engineered variants of sperm whale myoglobin catalyze this synthetically valuable c-c bond-forming transformation with high efficiency and product conversions across a variety of sulfide substrates (e.g., aryl-, benzyl-, and alkyl-substituted allylic sulfides) and α-diazo esters. moreover, the scope of this myoglobin-mediated transformati ... | 2016 | 27647732 |
| cultural hitchhiking in the matrilineal whales. | five species of whale with matrilineal social systems (daughters remain with mothers) have remarkably low levels of mitochondrial dna diversity. non-heritable matriline-level demography could reduce genetic diversity but the required conditions are not consistent with the natural histories of the matrilineal whales. the diversity of nuclear microsatellites is little reduced in the matrilineal whales arguing against bottlenecks. selective sweeps of the mitochondrial genome are feasible causes but ... | 2017 | 28275880 |
| sperm whales reduce foraging effort during exposure to 1-2 khz sonar and killer whale sounds. | the time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (dtag) attached to 12 sperm whales (physeter macrocephalus) using suction cups. behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an ... | 2016 | 27039511 |
| sperm whale predator-prey interactions involve chasing and buzzing, but no acoustic stunning. | the sperm whale carries a hypertrophied nose that generates powerful clicks for long-range echolocation. however, it remains a conundrum how this bizarrely shaped apex predator catches its prey. several hypotheses have been advanced to propose both active and passive means to acquire prey, including acoustic debilitation of prey with very powerful clicks. here we test these hypotheses by using sound and movement recording tags in a fine-scale study of buzz sequences to relate the acoustic behavi ... | 2016 | 27340122 |
| bindings of no, co, and o2 to multi-functional globin type dehaloperoxidase follow the "sliding scale rule". | dehaloperoxidase-hemoglobin (dhp), a multifunctional globin protein, functions not only as an oxygen carrier as typical globins such as myoglobin, but also as a peroxidase, a mono- and di-oxygenase, peroxygenase, and an oxidase. kinetics of dhp binding to no, co, and o2 were characterized for wild type dhp a and b and the h55d and h55v dhp a mutants. all three gaseous ligands bind to dhp significantly more weakly than sperm whale myoglobin (swmb). both co and no bind to dhp in a one-step process ... | 2017 | 28899945 |
| sw apomb amyloid aggregation under nondenaturing conditions: the role of native structure stability. | investigation of the molecular mechanisms underlying amyloid-related human diseases attracts close attention. these diseases, the number of which currently is above 40, are characterized by formation of peptide or protein aggregates containing a cross-β structure. most of the amyloidogenesis mechanisms described so far are based on experimental studies of aggregation of short peptides, intrinsically disordered proteins, or proteins under denaturing conditions, and studies of amyloid aggregate fo ... | 2017 | 28877500 |
| the energy based characteristics of sperm whale clicks using the hilbert huang transform analysis method. | in this paper, a unique analysis method for sperm whale clicks based on hilbert-huang transform (hht) is proposed. four sperm whale click samples with durations of 10 ms (defined as click i), and four sperm whale click samples with durations of 5 ms (defined as click ii) were illustrated. these click samples were recorded in the mediterranean sea by centro interdisciplinare di bioacusticae ricerche ambientali, università degli studi di pavia. the empirical mode decomposition method was used to d ... | 2017 | 28863586 |
| mismatch between the eye and the optic lobe in the giant squid. | giant squids (architeuthis) are a legendary species among the cephalopods. they live in the deep sea and are well known for their enormous body and giant eyes. it has been suggested that their giant eyes are not adapted for the detection of either mates or prey at distance, but rather are best suited for monitoring very large predators, such as sperm whales, at distances exceeding 120 m and at a depth below 600 m (nilsson et al. 2012 curr. biol.22, 683-688. (doi:10.1016/j.cub.2012.02.031)). howe ... | 2017 | 28791156 |
| characterization of heme orientational disorder in a myoglobin reconstituted with a trifluoromethyl-group-substituted heme cofactor. | the orientation of a cf3-substituted heme in sperm whale myoglobin and l29f, h64l, l29f/h64q, and h64q variant proteins has been investigated using (19)f nmr spectroscopy to elucidate structural factors responsible for the thermodynamic stability of the heme orientational disorder, i.e., the presence of two heme orientations differing by a 180° rotation about the 5-15 meso axis, with respect to the protein moiety. crystal structure of the met-aquo form of the wild-type myoglobin reconstituted wi ... | 2017 | 28758387 |
| application of dual frequency identification sonar for the study of deep diving odontocetes prey fields. | a dual frequency identification sonar was used to estimate density and size of potential deep diving odontocetes' prey in deep sea scattering layers in hawaii. size distributions data showed a bimodal pattern, with a population of data above the 50 cm of length, possibly big squids, and a population of data below 50 cm, mainly micronekton. the number of animals bigger than 50 cm was correlated with the length of the peak of the frequency distribution. data suggest that big predators, like squids ... | 2017 | 28679256 |
| nitrophorins and nitrobindins: structure and function. | classical all α-helical globins are present in all living organisms and are ordered in three lineages: (i) flavohemoglobins and single domain globins, (ii) protoglobins and globin coupled sensors and (iii) truncated hemoglobins, displaying the 3/3 or the 2/2 all α-helical fold. however, over the last two decades, all β-barrel and mixed α-helical-β-barrel heme-proteins displaying heme-based functional properties (e.g. ligand binding, transport and sensing) closely similar to those of all α-helica ... | 2017 | 28574374 |
| analysis of lethal and sublethal impacts of environmental disasters on sperm whales using stochastic modeling. | mathematical models are essential for combining data from multiple sources to quantify population endpoints. this is especially true for species, such as marine mammals, for which data on vital rates are difficult to obtain. since the effects of an environmental disaster are not fixed, we develop time-varying (nonautonomous) matrix population models that account for the eventual recovery of the environment to the pre-disaster state. we use these models to investigate how lethal and sublethal imp ... | 2017 | 28500397 |
| size and shape variations of the bony components of sperm whale cochleae. | several mass strandings of sperm whales occurred in the north sea during january and february 2016. twelve animals were necropsied and sampled around 48 h after their discovery on german coasts of schleswig holstein. the present study aims to explore the morphological variation of the primary sensory organ of sperm whales, the left and right auditory system, using high-resolution computerised tomography imaging. we performed a quantitative analysis of size and shape of cochleae using landmark-ba ... | 2017 | 28440286 |
| a personal perspective: my four encounters with john kendrew. | by celebrating the 100th anniversary of john kendrew's birth in 1917, the journal of molecular biology recognizes his seminal contributions to science in general and structural biology in particular. john was first to use x-ray diffraction to solve the 3-dimensional structure of a protein, sperm-whale myoglobin, worthy of a nobel prize in chemistry in 1962. john was the founder and first editor-in-chief of the journal of molecular biology, deputy chairman of the laboratory of molecular biology a ... | 2017 | 28433537 |
| chromatographic and spectral studies of jetsam and archived ambergris. | we describe determination of the dichloromethane-soluble components of 12 samples of the natural product, ambergris, using capillary gas chromatography-mass spectrometry (gc-ms). ambergris is produced in vivo in about 1% of sperm whales and is used in perfumery and for odour fixation. whilst descriptions of ambergris chemistry appeared until about 40 years ago, few accounts of analyses of whole extracts of multiple samples of ambergris by gc-ms have been published before. as expected, our analys ... | 2017 | 28278659 |
| effect of 4-hydroxy-2-nonenal on myoglobin-mediated lipid oxidation when varying histidine content and hemin affinity. | the compound 4-hydroxy-2-nonenal (hne) dissolved in water was examined to remove potential effects of using ethanol to solubilize the aldehyde such as altering protein structure or redox properties of myoglobin (mb). hne became covalently bound to sperm whale mb at up to five sites based on esi-ms analysis. adducted mb promoted lipid oxidation in washed muscle more effectively than non-adducted mb. alkylation of p88h/q152hmb with hne accelerated metmb formation and subsequent lipid oxidation. p8 ... | 2017 | 28274434 |
| thermal unfolding of myoglobin in the landau-ginzburg-wilson approach. | the landau-ginzburg-wilson paradigm is applied to model the low-temperature crystallographic cα backbone structure of sperm whale myoglobin. the glauber protocol is employed to simulate its response to an increase in ambient temperature. the myoglobin is found to unfold from its native state by a succession of α-helical intermediates, fully in line with the observed folding and unfolding patterns in denaturation experiments. in particular, a molten globule intermediate is identified with experim ... | 2016 | 28085346 |
| cetacean mass strandings and multidisciplinary work. | | 2016 | 26800488 |
| properties and architecture of the sperm whale skull amphitheatre. | the sperm whale skull amphitheatre cradles an enormous two-tonne spermaceti organ. the amphitheatre separates this organ from the cranium and the cervical vertebrae that lie in close proximity to the base of the skull. here, we elucidate that this skull amphitheatre is an elastic, flexible, triple-layered structure with mechanical properties that are conjointly guided by bone histology and the characteristics of pore space. we contend that the amphitheatre will flex elastically to equilibrate fo ... | 2016 | 26781232 |
| characterization of ground state electron configurations of high-spin quintet ferrous heme iron in deoxy myoglobin reconstituted with trifluoromethyl group-substituted heme cofactors. | we introduced trifluoromethyl (cf3) group(s) as heme side chain(s) of sperm whale myoglobin (mb) in order to characterize the electronic nature of heme fe(ii) in deoxy mb using (19)f nmr spectroscopy. on the basis of the anti-curie behavior of cf3 signals, we found that the deoxy mb is in thermal equilibrium between the (5)b2, (dxy)(2)(dxz)(dyz)(dz(2))(dx(2)-y(2)), and (5)e, (dxy)(dxz)(2)(dyz)(dz(2))(dx(2)-y(2)), states of the heme fe(ii), i.e., (5)b2 ⇆ (5)e. analysis of the curvature in curie p ... | 2016 | 27934434 |
| cultural turnover among galápagos sperm whales. | while populations may wax and wane, it is rare for an entire population to be replaced by a completely different set of individuals. we document the large-scale relocation of cultural groups of sperm whale off the galápagos islands, in which two sympatric vocal clans were entirely replaced by two different ones. between 1985 and 1999, whales from two clans (called regular and plus-one) defined by cultural dialects in coda vocalizations were repeatedly photo-identified off galápagos. their occurr ... | 2016 | 27853582 |
| temporal and spatial variation of beaked and sperm whales foraging activity in hawai'i, as determined with passive acoustics. | beaked and sperm whales are top predators living in the waters off the kona coast of hawai'i. temporal and spatial analyses of the foraging activity of these two species were studied with passive acoustics techniques. three passive acoustics recorders moored to the ocean floor were used to monitor the foraging activity of these whales in three locations along the kona coast of the island of hawaii. data were analyzed using automatic detector/classification systems: m3r (marine mammal monitoring ... | 2016 | 27794335 |
| mediterranean sperm whales, physeter macrocephalus: the precarious state of a lost tribe. | first observed in the classical era, a population of sperm whales (physeter macrocephalus) persists to this day in the deep waters of the mediterranean sea. genetic and observational evidence support the notion that this is an isolated population, separated from its atlantic neighbours. these whales depend on mesopelagic squid for food, and appear to occupy a very similar ecological niche to sperm whales in the open oceans. recent evidence proving that individuals can pass between the eastern an ... | 2017 | 27770991 |
| critical decline of the eastern caribbean sperm whale population. | sperm whale (physeter macrocephalus) populations were expected to rebuild following the end of commercial whaling. we document the decline of the population in the eastern caribbean by tracing demographic changes of well-studied social units. we address hypotheses that, over a ten-year period of dedicated effort (2005-2015), unit size, numbers of calves and/or calving rates have each declined. across 16 units, the number of adults decreased in 12 units, increased in two, and showed no change in ... | 2016 | 27706153 |
| stretching the truth: length data highlight falsification of japanese sperm whale catch statistics in the southern hemisphere. | falsification of reports on japanese catches of sperm whales (physeter macrocephalus) is known to have occurred at both land whaling stations and in north pacific factory fleets. here, we conduct an analysis of pelagic sperm whale catches in the southern hemisphere: we compare true soviet length data from the yuri dolgorukiy factory fleet during 1960-1975 to data for the same period reported to the international whaling commission (iwc) by japan. prior to implementation of the international obse ... | 2016 | 27703712 |
| analysis of mercury and methylmercury concentrations, and selenium:mercury molar ratios for a toxicological assessment of sperm whales (physeter macrocephalus) in the most recent stranding event along the adriatic coast (southern italy, mediterranean sea). | mass stranding of sperm whales (physeter macrocephalus) is a rare event in the mediterranean sea. in september 2014, a pod of seven sperm whales became stranded along the adriatic coast of southern italy. this is the seventh occurrence of this type since 1555 in this sea basin. total concentrations of mercury (t-hg), methylmercury (mehg) and selenium (se) were measured from brain, muscle, liver and kidney of three female sperm whales, which died in this event. analyses showed considerable, age-d ... | 2015 | 26233668 |
| organometallic myoglobins: formation of fe-carbon bonds and distal pocket effects on aryl ligand conformations. | bioorganometallic fe-c bonds are biologically relevant species that may result from the metabolism of natural or synthetic hydrazines. the molecular structures of four new sperm whale mutant myoglobin derivatives with fe-aryl moieties, namely h64a-tolyl-m, h64a-chlorophenyl-p, h64q-tolyl-m, and h64q-chlorophenyl-p, have been determined at 1.7-1.9å resolution. the structures reveal conformational preferences for the substituted aryls resulting from attachment of the aryl ligands to fe at the site ... | 2016 | 27687333 |
| large amounts of marine debris found in sperm whales stranded along the north sea coast in early 2016. | 30 sperm whales (physeter macrocephalus) stranded along the coasts of the north sea between january and february 2016. the gastro-intestinal tracts of 22 of the carcasses were investigated. marine debris including netting, ropes, foils, packaging material and a part of a car were found in nine of the 22 individuals. here we provide details about the findings and consequences for the animals. while none of the items was responsible for the death of the animal, the findings demonstrate the high le ... | 2016 | 27539635 |
| correction: evolutionary patterns among living and fossil kogiid sperm whales: evidence from the neogene of central america. | | 2015 | 25992650 |
| socially segregated, sympatric sperm whale clans in the atlantic ocean. | sperm whales (physeter macrocephalus) are unusual in that there is good evidence for sympatric populations with distinct culturally determined behaviour, including potential acoustic markers of the population division. in the pacific, socially segregated, vocal clans with distinct dialects coexist; by contrast, geographical variation in vocal repertoire in the atlantic has been attributed to drift. we examine networks of acoustic repertoire similarity and social interactions for 11 social units ... | 2016 | 27429766 |
| inactivation of the olfactory marker protein (omp) gene in river dolphins and other odontocete cetaceans. | various toothed whales (odontoceti) are unique among mammals in lacking olfactory bulbs as adults and are thought to be anosmic (lacking the olfactory sense). at the molecular level, toothed whales have high percentages of pseudogenic olfactory receptor genes, but species that have been investigated to date retain an intact copy of the olfactory marker protein gene (omp), which is highly expressed in olfactory receptor neurons and may regulate the temporal resolution of olfactory responses. one ... | 2017 | 28193458 |
| how to build a deep diver: the extreme morphology of mesoplodonts. | mesoplodont beaked whales are extreme divers, diving for over 45 mins and to depths of over 800 m. these dives are of similar depth and duration to those of the giant sperm whale (physeter macrocephalus) whose body mass can be 50 times larger. velten et al. (2013) provided anatomical data that demonstrated that on-board oxygen stores were sufficient to aerobically support the extreme dives of mesoplodonts if their diving metabolic rates are low. because no physiological data yet exist, we utiliz ... | 2016 | 27940620 |
| correction: abundance and distribution of sperm whales in the canary islands: can sperm whales in the archipelago sustain the current level of ship-strike mortalities? | [this corrects the article doi: 10.1371/journal.pone.0150660.]. | 2017 | 27144683 |
| a novel tyrosine-heme c−o covalent linkage in f43y myoglobin: a new post-translational modification of heme proteins. | heme post-translational modification plays a key role in tuning the structure and function of heme proteins. we herein report a novel tyrosine-heme covalent c−o bond in an artificially produced sperm whale myoglobin (mb) mutant, f43y mb, which formed spontaneously in vivo between the tyr43 hydroxy group and the heme 4-vinyl group. this highlights the diverse chemistry of heme post-translational modifications, and lays groundwork for further investigation of the structural and functional diversit ... | 2015 | 25392956 |
| architecture of the sperm whale forehead facilitates ramming combat. | herman melville's novel moby dick was inspired by historical instances in which large sperm whales (physeter macrocephalus l.) sank 19th century whaling ships by ramming them with their foreheads. the immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. it contains two large oil-filled compartments, known as the "spermaceti organ" and "junk," that constitute up to one-quarter of body mass and extend one-third of the tota ... | 2016 | 27069822 |
| tracking evolution of myoglobin stability in cetaceans using experimentally calibrated computational methods that account for generic protein relaxation. | the evolution of cetaceans (whales, dolphins, and porpoises) from land to water is one of the most spectacular events in mammal evolution. it has been suggested that selection for higher myoglobin stability (∆g of folding) allowed whales to conquer the deep-diving niche. the stability of multi-site protein variants, including ancient proteins, is however hard to describe theoretically. from a compilation of experimental ∆∆g vs. ∆g we first find that protein substitutions are subject to large gen ... | 2016 | 27068539 |
| what influences the worldwide genetic structure of sperm whales (physeter macrocephalus)? | the interplay of natural selection and genetic drift, influenced by geographic isolation, mating systems and population size, determines patterns of genetic diversity within species. the sperm whale provides an interesting example of a long-lived species with few geographic barriers to dispersal. worldwide mtdna diversity is relatively low, but highly structured among geographic regions and social groups, attributed to female philopatry. however, it is unclear whether this female philopatry is d ... | 2016 | 27037911 |
| dna cleavage by oxymyoglobin and cysteine-introduced metmyoglobin. | double stranded dna was cleaved oxidatively by incubation with oxygenated myoglobin, and lys96cys sperm whale myoglobin in its stable ferric form functioned as an artificial nuclease under air by formation of an oxygenated species, owing to electron transfer from the sh group of the introduced cysteine to the heme. | 2014 | 25327831 |
| sperm whale codas may encode individuality as well as clan identity. | sperm whales produce codas for communication that can be grouped into different types according to their temporal patterns. codas have led researchers to propose that sperm whales belong to distinct cultural clans, but it is presently unclear if they also convey individual information. coda clicks comprise a series of pulses and the delay between pulses is a function of organ size, and therefore body size, and so is one potential source of individual information. another potential individual-spe ... | 2016 | 27250178 |
| deer sensitivity between iron centers and nitroxides in heme-containing proteins improves dramatically using broadband, high-field epr. | this work demonstrates the feasibility of making sensitive nanometer distance measurements between fe(iii) heme centers and nitroxide spin labels in proteins using the double electron-electron resonance (deer) pulsed epr technique at 94 ghz. techniques to measure accurately long distances in many classes of heme proteins using deer are currently strongly limited by sensitivity. in this paper we demonstrate sensitivity gains of more than 30 times compared with previous lower frequency (x-band) de ... | 2016 | 27035368 |
| abundance and distribution of sperm whales in the canary islands: can sperm whales in the archipelago sustain the current level of ship-strike mortalities? | sperm whales are present in the canary islands year-round, suggesting that the archipelago is an important area for this species in the north atlantic. however, the area experiences one of the highest reported rates of sperm whale ship-strike in the world. here we investigate if the number of sperm whales found in the archipelago can sustain the current rate of ship-strike mortality. the results of this study may also have implications for offshore areas where concentrations of sperm whales may ... | 2016 | 26999791 |
| habitat-based cetacean density models for the u.s. atlantic and gulf of mexico. | cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. pursuant to the urgent need for this knowledge for the u.s. atlantic and gulf of mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing an ... | 2016 | 26936335 |
| individual, unit and vocal clan level identity cues in sperm whale codas. | the 'social complexity hypothesis' suggests that complex social structure is a driver of diversity in animal communication systems. sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as 'codas'. we examined variation in coda repertoires among both individual whales and social units-the basic element of sperm whale society-using data from n ... | 2016 | 26909165 |
| endo- and ectoparasites of large whales (cetartiodactyla: balaenopteridae, physeteridae): overcoming difficulties in obtaining appropriate samples by non- and minimally-invasive methods. | baleen and sperm whales, belonging to the order cetartiodactyla, are the largest and heaviest existent mammals in the world, collectively known as large whales. large whales have been subjected to a variety of conservation means, which could be better monitored and managed if physiological and pathophysiological information, such as pathogen infections, could already be gathered from free-swimming animals instead of carcasses. parasitic diseases are increasingly recognized for their profound inf ... | 2015 | 26835249 |
| the heavy metals cadmium, lead and mercury in raw materials of animal origin: evaluation of data from practice. | raw materials from animal origin are widely used in homoeopathy. due to the lack of dedicated limits, the quality requirements for herbal drugs of the european pharmacopoeia (ph. eur.) and/or the german homoeopathic pharmacopoeia (homöopathisches arzneibuch, hab), including limits for heavy metals such as cadmium, lead and mercury, have been applied. a recent database evaluation shows that for some raw materials of animal origin the ph. eur. limits for herbal drugs cannot be met in practice. for ... | 2015 | 26830164 |
| effects of heme electronic structure and distal polar interaction on functional and vibrational properties of myoglobin. | we analyzed the oxygen (o2) and carbon monoxide (co) binding properties, autoxidation reaction rate, and feo2 and feco vibrational frequencies of the h64q mutant of sperm whale myoglobin (mb) reconstituted with chemically modified heme cofactors possessing a variety of heme fe electron densities (ρ(fe)), and the results were compared with those for the previously studied native [shibata, t. et al. j. am. chem. soc. 2010, 132, 6091-6098], and h64l [nishimura, r. et al. inorg. chem. 2014, 53, 1091 ... | 2016 | 26814981 |
| response to: letter to the editor: "cetacean mass stranding and multidisciplinary work". | | 2016 | 26812371 |
| size distribution of sperm whales acoustically identified during long term deep-sea monitoring in the ionian sea. | the sperm whale (physeter macrocephalus) emits a typical short acoustic signal, defined as a "click", almost continuously while diving. it is produced in different time patterns to acoustically explore the environment and communicate with conspecifics. each emitted click has a multi-pulse structure, resulting from the production of the sound within the sperm whale's head. a stable inter pulse interval (stable ipi) can be identified among the pulses that compose a single click. applying specific ... | 2015 | 26675588 |
| passive acoustic monitoring of the environmental impact of oil exploration on marine mammals in the gulf of mexico. | the gulf of mexico is a region densely populated by marine mammals that must adapt to living in a highly active industrial environment. this paper presents a new approach to quantifying the anthropogenic impact on the marine mammal population. the results for sperm and beaked whales of a case study of regional population dynamics trends after the deepwater horizon oil spill, derived from passive acoustic-monitoring data gathered before and after the spill in the vicinity of the accident, are pre ... | 2016 | 26611062 |
| what's the catch? validity of whaling data for japanese catches of sperm whales in the north pacific. | the failure of international efforts to manage commercial whaling was exemplified by revelations of large-scale illegal whale catches by the ussr over a 30 year period following world war ii. falsifications of catch data have also been reported for japanese coastal whaling, but to date there has been no investigation of the reliability of catch statistics for japanese pelagic (factory fleet) whaling operations. here, we use data of known reliability from soviet whaling industry reports to show t ... | 2015 | 26587276 |
| global assessment of cadmium concentrations in the skin of free-ranging sperm whales (physeter macrocephalus). | cadmium is a non-essential, toxic metal found accumulated in the organs of stranded cetaceans. currently, there is no baseline cadmium concentration reported in a free-ranging, pelagic cetacean. the aim was to determine cadmium concentrations in the skin of free-ranging sperm whales (n=340) collected from 16 regions around the world during the voyage of the odyssey (2000-2005) considering region, gender, and age in males. cadmium was detected in 81% of skin biopsies with a mean of 0.3±0.04μg/g w ... | 2015 | 26456815 |
| multilevel animal societies can emerge from cultural transmission. | multilevel societies, containing hierarchically nested social levels, are remarkable social structures whose origins are unclear. the social relationships of sperm whales are organized in a multilevel society with an upper level composed of clans of individuals communicating using similar patterns of clicks (codas). using agent-based models informed by an 18-year empirical study, we show that clans are unlikely products of stochastic processes (genetic or cultural drift) but likely originate fro ... | 2015 | 26348688 |
| a designed metalloenzyme achieving the catalytic rate of a native enzyme. | terminal oxidases catalyze four-electron reduction of oxygen to water, and the energy harvested is utilized to drive the synthesis of adenosine triphosphate. while much effort has been made to design a catalyst mimicking the function of terminal oxidases, most biomimetic catalysts have much lower activity than native oxidases. herein we report a designed oxidase in myoglobin with an o2 reduction rate (52 s(-1)) comparable to that of a native cytochrome (cyt) cbb3 oxidase (50 s(-1)) under identic ... | 2015 | 26318313 |
| intermolecular carbene s-h insertion catalysed by engineered myoglobin-based catalysts†. | the first example of a biocatalytic strategy for the synthesis of thioethers via an intermolecular carbene s-h insertion reaction is reported. engineered variants of sperm whale myoglobin were found to efficiently catalyze this c-s bond forming transformation across a diverse set of aryl and alkyl mercaptan substrates and α-diazoester carbene donors, providing high conversions (60-99%) and high numbers of catalytic turnovers (1,100-5,400). furthermore, the enantioselectivity of these biocatalyst ... | 2015 | 26101581 |
| towards a "golden standard" for computing globin stability: stability and structure sensitivity of myoglobin mutants. | fast and accurate computation of protein stability is increasingly important for e.g. protein engineering and protein misfolding diseases, but no consensus methods exist for important proteins such as globins, and performance may depend on the type of structural input given. this paper reports benchmarking of six protein stability calculators (popmusic 2.1, i-mutant 2.0, i-mutant 3.0, cupsat, sdm, and mcsm) against 134 experimental stability changes for mutations of sperm-whale myoglobin. six di ... | 2015 | 26054434 |
| enzymes for synthetic biology of ambroxide-related diterpenoid fragrance compounds. | ambrox and related ambroxides are highly priced in the fragrance industry, and valued for their delicate odor and fixative properties. historically, ambrox was obtained from ambergris, a waxy excretion produced by sperm whales, now an endangered species. synthetic ambroxides have replaced ambergris in perfume manufacture. plant labdane diterpenoids can serve as starting material for ambroxide synthesis. among these, the diterpene alcohol sclareol is the major industrial precursor obtained from c ... | 2015 | 25846965 |
| sperm whales ability to avoid approaching vessels is affected by sound reception in stratified waters. | collision with vessels is a major cause of whale mortality in the mediterranean sea. the effect of non-spherical sound propagation effects on received levels (rl) was investigated for the sperm whale (physeter macrocephalus). relevant dive patterns were considered in each case and the rl were compared for two periods using a ray tracing software, the winter conditions and the summer stratified situation. rl were plotted as a function of time in a simulated collision case for two vessel speeds re ... | 2015 | 25843440 |
| significantly enhanced heme retention ability of myoglobin engineered to mimic the third covalent linkage by nonaxial histidine to heme (vinyl) in synechocystis hemoglobin. | heme proteins, which reversibly bind oxygen and display a particular fold originally identified in myoglobin (mb), characterize the "hemoglobin (hb) superfamily." the long known and widely investigated hb superfamily, however, has been enriched by the discovery and investigation of new classes and members. truncated hbs typify such novel classes and exhibit a distinct two-on-two α-helical fold. the truncated hb from the freshwater cyanobacterium synechocystis exhibits hexacoordinate heme chemist ... | 2015 | 25451928 |
| principal component analysis reveals correlation of cavities evolution and functional motions in proteins. | protein conformation has been recognized as the key feature determining biological function, as it determines the position of the essential groups specifically interacting with substrates. hence, the shape of the cavities or grooves at the protein surface appears to drive those functions. however, only a few studies describe the geometrical evolution of protein cavities during molecular dynamics simulations (md), usually with a crude representation. to unveil the dynamics of cavity geometry evol ... | 2015 | 25424655 |
| effects of decalcification on bulk and compound-specific nitrogen and carbon isotope analyses of dentin. | for bulk carbon and nitrogen isotope analysis of dentin, samples are typically decalcified. since the non-protein carbon in dentin is low, whole sample analysis may produce reliable data. compound-specific isotope analysis (csia) of bone and tooth dentin protein is a powerful tool for reconstructing the flow of carbon and nitrogen in modern and past food webs. decalcification has also been used to prepare bone and dentin samples for csia, but the effects of this process on bulk dentin, amino aci ... | 2014 | 25380497 |
| structures of k42n and k42y sperm whale myoglobins point to an inhibitory role of distal water in peroxidase activity. | sperm whale myoglobin (mb) functions as an oxygen-storage protein, but in the ferric state it possesses a weak peroxidase activity which enables it to carry out h2o2-dependent dehalogenation reactions. hemoglobin/dehaloperoxidase from amphitrite ornata (dhp) is a dual-function protein represented by two isoproteins dhp a and dhp b; its peroxidase activity is at least ten times stronger than that of mb and plays a physiological role. the `dhp a-like' k42y mb mutant (k42y) and the `dhp b-like' k42 ... | 2014 | 25372675 |
| carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer california current. | climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore california current system (ccs) by measuring δ15n and δ13c values of amino acids in a top predator, the sperm whale (physeter macrocephalus). using a time series of skin ti ... | 2014 | 25329915 |
| using models of social transmission to examine the spread of longline depredation behavior among sperm whales in the gulf of alaska. | fishing, farming and ranching provide opportunities for predators to prey on resources concentrated by humans, a behavior termed depredation. in the gulf of alaska, observations of sperm whales depredating on fish caught on demersal longline gear dates back to the 1970s, with reported incidents increasing in the mid-1990s. sperm whale depredation provides an opportunity to study the spread of a novel foraging behavior within a population. data were collected during national marine fisheries serv ... | 2014 | 25272019 |
| electronic control of ligand-binding preference of a myoglobin mutant. | the l29f mutant of sperm whale myoglobin (mb), where the leucine 29 residue was replaced by phenylalanine (phe), was shown to exhibit remarkably high affinity to oxygen (o2), possibly due to stabilization of the heme fe atom-bound o2 in the mutant protein through a proposed unique electrostatic interaction with the introduced phe29, in addition to well-known hydrogen bonding with his64 [carver, t. e.; brantley, r. e.; singleton, e. w.; arduini, r. m.; quillin, m. l.; phillips, g. n., jr.; olson, ... | 2014 | 25111253 |
| cobaloxime-based artificial hydrogenases. | cobaloximes are popular h2 evolution molecular catalysts but have so far mainly been studied in nonaqueous conditions. we show here that they are also valuable for the design of artificial hydrogenases for application in neutral aqueous solutions and report on the preparation of two well-defined biohybrid species via the binding of two cobaloxime moieties, {co(dmgh)2} and {co(dmgbf2)2} (dmgh2 = dimethylglyoxime), to apo sperm-whale myoglobin (swmb). all spectroscopic data confirm that the cobalo ... | 2014 | 25029381 |
| using a coherent hydrophone array for observing sperm whale range, classification, and shallow-water dive profiles. | sperm whales in the new england continental shelf and slope were passively localized, in both range and bearing, and classified using a single low-frequency (<2500 hz), densely sampled, towed horizontal coherent hydrophone array system. whale bearings were estimated using time-domain beamforming that provided high coherent array gain in sperm whale click signal-to-noise ratio. whale ranges from the receiver array center were estimated using the moving array triangulation technique from a sequenc ... | 2014 | 24907798 |
| chemical dispersants used in the gulf of mexico oil crisis are cytotoxic and genotoxic to sperm whale skin cells. | the 2010 deepwater horizon oil rig explosion in the gulf of mexico drew attention to the need for toxicological studies of chemical dispersants. we are still learning the effects these spills had on wildlife. little is known about the toxicity of these substances in marine mammals. the objective of this study was to determine the toxicity of the two dispersants (corexit 9500 and 9527). corexit 9500 and 9527 were both cytotoxic to sperm whale skin fibroblasts. corexit 9527 was less cytotoxic than ... | 2014 | 24813266 |
| conformational substates of myoglobin intermediate resolved by picosecond x-ray solution scattering. | conformational substates of proteins are generally considered to play important roles in regulating protein functions, but an understanding of how they influence the structural dynamics and functions of the proteins has been elusive. here, we investigate the structural dynamics of sperm whale myoglobin associated with the conformational substates using picosecond x-ray solution scattering. by applying kinetic analysis considering all of the plausible candidate models, we establish a kinetic mode ... | 2014 | 24761190 |
| repeated mass strandings of miocene marine mammals from atacama region of chile point to sudden death at sea. | marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (habs). because algal toxins cause organ failure in marine mammals, habs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. toxin-mediated mortalities in marine food webs have the potential to occur ove ... | 2014 | 24573855 |
| global assessment of arsenic pollution using sperm whales (physeter macrocephalus) as an emerging aquatic model organism. | arsenic is an oceanic pollutant of global concern due to its toxicity, ability to bioaccumulate and continued input into the environment by anthropogenic activities. the sperm whale (physeter macrocephalus) is an emerging aquatic model for both human disease and ocean health having global distribution and high trophic level. the aim of this study was to establish global and regional baselines of total arsenic concentrations using free-ranging sperm whales. skin biopsies (n=342) were collected du ... | 2014 | 24473067 |
| influence of heme environment structure on dioxygen affinity for the dual function amphitrite ornata hemoglobin/dehaloperoxidase. insights into the evolutional structure-function adaptations. | sea worm, amphitrite ornata, has evolved its globin (an o(2) carrier) also to serves as a dehaloperoxidase (dhp) to detoxify haloaromatic pollutants generated by competing species. a previous mutagenesis study by our groups on both dhp and sperm whale myoglobin (sw mb) revealed some structural factors that influence the dehaloperoxidase activities (significantly lower for mb) of both proteins. using an isocyanide/o(2) partition constant measurement method in this study, we have examined the effe ... | 2014 | 24440609 |
| the production of nitrous oxide by the heme/nonheme diiron center of engineered myoglobins (fe(b)mbs) proceeds through a trans-iron-nitrosyl dimer. | denitrifying no reductases are transmembrane protein complexes that are evolutionarily related to heme/copper terminal oxidases. they utilize a heme/nonheme diiron center to reduce two no molecules to n2o. engineering a nonheme fe(b) site within the heme distal pocket of sperm whale myoglobin has offered well-defined diiron clusters for the investigation of the mechanism of no reduction in these unique active sites. in this study, we use ftir spectroscopy to monitor the production of n2o in solu ... | 2014 | 24432820 |