Artisanal shark fisheries have been an important source of food and employment in Mexico for many years. In the Gulf Mexico, this multispecific fishery is based on seasonal abundance several teleost species. To obtain biological information needed to manage conserve stocks, intensive monitoring artisanal landings was undertaken from November 1993 December 1994. The State Campeche had highest effort. October 1994 monthly catch per unit effort all species areas combined (27.2 sharks trip)....

Growth-temperature-dependent alterations in the total extractable lipid and polar components of two strains Thermus sp. isolated from a Portuguese hot spring were studied between 50°C 78°C. The varied 8·0 10·6% cell dry weight; there no phosphorus carotenoid content extract, but carbohydrate increased as growth temperature was raised. Three glycolipids four phospholipids separated by thin-layer chromatography. relative concentration major glycolipid (GL1) strain SPS 17 (yellow-pigmented)...

Significance Although the human disaggregase machinery has been shown to disassemble mature α-synuclein amyloid fibrils, molecular mechanism that drives process remained elusive. In this work, we show disassembly is initiated by destabilization of fibril ends, followed fast propagation protofilament unzipping and depolymerization along axis. This results in an all-or-none disaggregation individual aggregates, avoiding accumulation harmful intermediate aggregated species. We specifically...

Nucleoplasmin (NP) is a pentameric chaperone that regulates the condensation state of chromatin extracting specific basic proteins from sperm and depositing H2A-H2B histone dimers. It has been proposed histones could bind to either lateral or distal face structure. Here, we combine different biochemical biophysical techniques show natural, hyperphosphorylated NP can five dimers amount bound ligand depends on overall charge (phosphorylation level) chaperone. Three-dimensional reconstruction...

Nucleoplasmin (NP) is a histone chaperone involved in nucleosome assembly, chromatin decondensation at fertilization, and apoptosis. To carry out these activities NP has to interact with different types of histones, an interaction that regulated by phosphorylation. Here we have identified number phosphorylated residues mass spectrometry generated mutants which amino acids are replaced Asp mimic the effect Our results show that, among eight phosphoryl groups experimentally detected, four...

Abstract Nucleoplasmin (NP) is an abundant histone chaperone in vertebrate oocytes and embryos involved storing releasing maternal histones to establish maintain the zygotic epigenome. NP has been considered a H2A–H2B recently it shown that can also interact with H3-H4. However, its interaction different types of not quantitatively studied so far. We show here binds H2A–H2B, H3-H4 linker K d values subnanomolar range, forming complexes. Post-translational modifications regulate exposure...

We have previously characterized the interaction of nucleoplasmin with core histones and studied possible involvement this chaperone molecule in transcription. Here we study chromatin. show that highly phosphorylated Xenopus laevis egg can unfold sperm somatic chromatin a way involves removal chromosomal proteins from linker DNA regions without stable nucleosome. The complexes between both sperm-specific been hydrodynamically using sedimentation equilibrium analytical ultracentrifuge....

The role of Nucleoplasmin (NP) as a H2A-H2B histone chaperone has been extensively characterized. To understand its putative interaction with other ligands, we have characterized ability to bind H3-H4 and octamers. We find that the forms distinct complexes histones, which differ in number molecules build assembly their spatial distribution. When complexed tetramers or octamers, two NP pentamers form an ellipsoidal particle histones located at center assembly, stark contrast NP/H2A-H2B...

In this paper, we present a review of sperm nuclear basic proteins (SNBPs) in teleost fish. The distribution the three groups SNBPs [histone (H)-type, protamine-like (PL)-type and protamine (P)-type], their evolution possible relation to mode fertilization are described. regard, have characterized from two closely related species Scorpaeniform fish: internally fertilizing Sebastes maliger externally Sebastolobus sp., both family Scorpaenidae. Despite different reproductive behavior these...

Fourier transform infrared spectroscopy, circular dichroism and prediction techniques have been used to investigate the conformational properties of nucleoplasmin isolated from oocytes eggs Xenopus. laevis overexpressed in Escherichia coli. A simple fast method allows purification recombinant free truncated and/or aggregated forms, therefore provides a suitable sample carry out structural functional comparison between these proteins. The secondary structure three proteins estimated both...

Sarcoplasmic reticulum Ca2+-ATPase structure and organization in the membrane has been studied by infrared spectroscopy decomposition of amide I band. Besides component bands assignable to secondary elements such as alpha-helix, beta-sheet, etc...., two unusual bands, one at 1,645 cm(-1) H2O buffer other 1,625 D2O are present. By perturbing protein using temperature limited proteolysis, band is tentatively assigned alpha-helical segments located cytoplasmic domain coupled beta-sheet...

The chromatin decondensation activity, thermal stability, and secondary structure of recombinant nucleoplasmin, two deletion mutants, the protein isolated from Xenopus oocytes have been characterized. As previously reported, activity recombinant, unphosphorylated nucleoplasmin is almost negligible. Our data show that 50 residues at C-terminal domain protein, containing positively charged nuclear localization sequence, activates its ability decreases stability. Interestingly, both stability...

The aggregation of α-synuclein is the hallmark a collective neurodegenerative disorders known as synucleinopathies. tendency to aggregate this protein, toxicity its intermediates and ability cellular protein quality control system clear these seems be regulated, among other factors, by post-translational modifications (PTMs). Among modifications, we consider herein proteolysis at both N- C-terminal regions factor that could modulate disassembly toxic amyloids human disaggregase, combination...

Abstract Nucleoplasmin (NP) is a pentameric histone chaperone that regulates the condensation state of chromatin in different cellular processes. We focus here on interaction NP with octamer, showing could bind sequentially components to assemble an octamer-like particle, and crosslinked octamers high affinity. The three-dimensional reconstruction NP/octamer complex generated by single-particle cryoelectron microscopy, revealed several intrinsically disordered tail domains two pentamers,...

Fourier transform infrared spectroscopy, circular dichroism and prediction techniques have been used to investigate the conformational properties of nucleoplasmin isolated from oocytes eggs Xenopus. laevis overexpressed in Escherichia coli. A simple fast method allows purification recombinant free truncated and/or aggregated forms, therefore provides a suitable sample carry out structural functional comparison between these proteins. The secondary structure three proteins estimated both...

B 16 mouse melanoma cells in monolayers may be satisfactorily fused with 50% PEG 1500. However, pre‐treatment detergents solution at low concentrations significantly increases fusion, up to 8‐fold some instances, without impairing cell viability. The practical and mechanistical implications of this finding are discussed.

The complete cDNA sequence of Xenopus laevis sperm specific proteins SP1 and SP2 has been determined. This information when taken together with N-terminal sequencing mass spectroscopy data indicates that these two share a product precursor relationship in which results from cleavage short peptide SP1. secondary tertiary structures have characterized using circular dichroism three dimension structure prediction. These structural analyses conclusively shown SP1/SP2 are related to the histone...