Effects of phosvitin phosphopeptide-Ca complex prepared by efficient enzymatic hydrolysis on calcium absorption and bone deposition of mice

Phosvitin(PV)was treated with high-temperature,mild pressure(HTMP),and enzyme combination,and then phosvitin phosphopeptides-calcium(PPP-Ca)complexes were prepared.The low-calcium specific pathogen free-Kunming(SPF-KM)mice were used to determine the effect of PPP-Ca complexes on intestinal calcium absorption and their utilization for bone formation.The serum calcium content was the highest with the HTMP-Enz-PPP-Ca treatment(2.19 mmol/L),and it significantly down-regulated the abnormal elevation of serum alkaline phosphatase(AKP)caused by calcium deficiency.The low-calcium control group had the lowest calcium deposited to the femur(80.41 mg/g)and the lowest femur bone mineral density(BMD)(0.17 g/cm^(3)),while HTMP-Enz-PPP-Ca significantly improved bone calcium content(94.33 mg/g)and BMD(0.29 g/cm^(3)).The micro-computed tomography(MCT)images showed that the femur with the normal control,PV-Ca,and HTMP-Enz-PPP-Ca treatments had a more compact,complete,and thicker trabecular network than the low-calcium and CaCl_(2)treatments.These results indicated that the organic calcium(HTMP-Enz-PPP-Ca)promoted calcium absorption and bone deposition,and the effect of HTMP-Enz-PPP-Ca was better than the inorganic CaCl_(2).

Preparation of Cerium Dioxide Functionalized Magnetic Layered Double Hydroxides for High-efficiency Phosphopeptide Enrichment

In this work,we prepared a material with magnetic nanoparticles(Fe_(3)O_(4))as core,layered double hydroxides(LDHs)as affinity shell,and cerium dioxide(CeO_(2))as functional molecules(denoted as Fe_(3)O_(4)@LDH-CeO_(2)).On the basis of combined immobilized metal ion affinity chromatography(IMAC)and metal oxide affinity chromatography(MOAC),Fe_(3)O_(4)@LDH-CeO_(2) was used to enrich phosphopeptides with high efficiency.The material exhibited high selectivity(α-casein:β-casein:BSA=1:1:5000,mass ratio),high recovery(95.87%),and good reusability of 10 times adsorption-desorption experiments.The feasibility of Fe_(3)O_(4)@LDH-CeO_(2) was further investigated by extracting phosphopeptides from biological samples(nonfat milk,serum,saliva,and A549 cell lysate).

Clinical evaluation of remineralization potential of casein phosphopeptide amorphous calcium phosphate nanocomplexes for enamel decalcification in orthodontics

Background Enamel decalcification in orthodontics is a concern for dentists and methods to remineralize these lesions are the focus of intense research. The aim of this study was to evaluate the remineralizing effect of casein phosphopeptide amorphous calcium phosphate （CPP-ACP） nanocomplexes on enamel decalcification in orthodontics. Methods Twenty orthodontic patients with decalcified enamel lesions during fixed orthodontic therapy were recruited to this study as test group and twenty orthodontic patients with the similar condition as control group. GC Tooth Mousse, the main component of which is CPP-ACP, was used by each patient of test group every night after tooth-brushing for six months. For control group, each patient was asked to brush teeth with toothpaste containing 1100 parts per million （ppm） of fluoride twice a day. Standardized intraoral images were taken for all patients and the extent of enamel decalcification was evaluated before and after treatment over this study period. Measurements were statistically compared by t test. Results After using CPP-ACP for six months, the enamel decalcification index （EDI） of all patients had decreased; the mean EDI before using CPP-ACP was 0.191＋0.025 and that after using CPP-ACP was 0.183＋0.023, the difference was significant （t=5.169, P 〈0.01）. For control group, the mean EDI before treatment was 0.188±0.037 and that after treatment was 0.187±0.046, the difference was not significant （t=1.711, P 〉0.05）. Conclusion CPP-ACP can effectively improve the demineralized enamel lesions during orthodontic treatment, so it has some remineralization potential for enamel decalcification in orthodontics.

Inherently hydrophilic mesoporous channel coupled with metal oxide for fishing endogenous salivary glycopeptides and phosphopeptides

Both glycosylation and phosphorylation exert crucial rule in multitudinous biological processes.For in-depth profiling of glycosylation and phosphorylation,a magnetic metal oxide is effectively coupled with inherently hydrophilic mesoporous channels(denoted as Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG).Based on the mechanism of hydrophilic interaction liquid chromatography(HILIC)and metal oxide affinity chromatography(MOAC),the Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG nanomaterial shows high capacity for simultaneously enriching glycopeptides and phosphopeptides.With human saliva collected in successive four days as practical biological sample,endogenous glycopeptides and phosphopeptides are efficiently enriched.Further gene ontology analysis reveals that the identified endogenous glycopeptides and phosphopeptides participate in diverse molecular functions and biological processes.This strategy is anticipated to promote variation analysis of salivary post-translational modifications.

Advances in preparation and bioactivity of phosvitin phosphopeptides

Phosvitin and its phosphopeptides contain a large amount of phosphorylated amino groups and exhibit a series of unique bioactivities including metal-binding,antioxidant,bacteriostatic and biomineralization activities due to strong interactions between phosphate groups and metal ions.In this article,the structures and preparation of phosvitin phosphopeptides,the interactions of phosphopeptides with metal ions,and the biological activities associated with their metal-binding capacity,as well as future potential application prospects are discussed.

^(11)B and ~7Li NMR Investigations of the Oxysulfide Glasses in Li_2S-B_2O_3 (-LiBr) Systems

Phosphopeptides were synthesized with bis-alkyloxy-N,N-dialkylphosphorfollowed by oxidation. Many hydroxyl groups in oligopeptides can be O-phosphorylated in onestep.

GreenPhos,a universal method for in-depth measurement of plant phosphoproteomes with high quantitative reproducibility

Protein phosphorylation regulates a variety of important cellular and physiological processes in plants.In-depth profiling of plant phosphoproteomes has been more technically challenging than that of animal phosphoproteomes.This is largely due to the need to improve protein extraction efficiency from plant cells,which have a dense cell wall,and to minimize sample loss resulting from the stringent sample clean-up steps required for the removal of a large amount of biomolecules interfering with phosphopeptide purification and mass spectrometry analysis.To this end,we developed a method with a streamlined workflow for highly efficient purification of phosphopeptides from tissues of various green organisms including Arabidopsis,rice,tomato,and Chlamydomonas reinhardtii,enabling in-depth identification with high quantitative reproducibility of about 11000 phosphosites,the greatest depth achieved so far with single liquid chromatography-mass spectrometry(LC-MS)runs operated in a data-dependent acquisition(DDA)mode.The mainstay features of the method are the minimal sample loss achieved through elimination of sample clean-up before protease digestion and of desalting before phosphopeptide enrichment and hence the dramatic increases of time-and cost-effectiveness.The method,named GreenPhos,combined with single-shot LC-MS,enabled in-depth quantitative identification of Arabidopsis phosphoproteins,including differentially phosphorylated spliceosomal proteins,at multiple time points during salt stress and a number of kinase substrate motifs.GreenPhos is expected to serve as a universal method for purification of plant phosphopeptides,which,if samples are further fractionated and analyzed by multiple LC-MS runs,could enable measurement of plant phosphoproteomes with an unprecedented depth using a given mass spectrometry technology.

PhoPepMass： A database and search tool assisting human phosphorylation peptide identification from mass spectrometry data

Protein phosphorylation, one of the most important protein post-translational modifications, is involved in various biological processes, and the identification of phosphorylation peptides （phosphopeptides） and their corresponding phosphorylation sites （phosphosites） will facilitate the understanding of the molecular mechanism and function of phosphorylation. Mass spectrometry （MS） provides a high- throughput technology that enables the identification of large numbers of phosphosites. PhoPepMass is designed to assist human phosphopeptide identification from MS data based on a specific database of phophopeptide masses and a multivariate hypergeometric matching algorithm. It contains 244,915 phosphosites from several public sources. Moreover, the accurate masses of peptides and fragments with phosphosites were calculated. It is the first database that provides a systematic resource for the query of phosphosites on peptides and their corresponding masses. This allows researchers to search certain proteins of which phosphosites have been reported, to browse detailed phosphopeptide and fragment information, to match masses from MS analyses with defined threshold to the corresponding phos- phopeptide, and to compare proprietary phosphopeptide discovery results with results from previous studies. Additionally, a database search software is created and a ＂two-stage search strategy＂ is suggested to identify phosphopeptides from tandem mass spectra of proteomics data. We expect PhoPepMass to be a useful tool and a source of reference for proteomics researchers.

Phosphoproteomics Analysis of Endometrium in Women with or without Endometriosis

Background：The molecular mechanisms underlying the endometriosis are still not completely understood.In order to test the hypothesis that the approaches in phosphoproteomics might contribute to the identification of key biomarkers to assess disease pathogenesis and drug targets,we carried out a phosphoproteomics analysis of human endometrium.Methods：A large-scale differential phosphoproteome analysis,using peptide enrichment of titanium dioxide purify and sequential elution from immobilized metal affinity chromatography with linear trap quadrupole-tandem mass spectrometry,was performed in endometrium tissues from 8 women with or without endometriosis.Results：The phosphorylation profiling of endometrium from endometriosis patients had been obtained,and found that identified 516 proteins were modified at phosphorylation level during endometriosis.Gene ontology annotation analysis showed that these proteins were enriched in cellular processes of binding and catalytic activity.Further pathway analysis showed that ribosome pathway and focal adhesion pathway were the top two pathways,which might be deregulated during the development of endometriosis.Conclusions：That large-scale phosphoproteome quantification has been successfully identified in endometrium tissues of women with or without endometriosis will provide new insights to understand the molecular mechanisms of the development of endometriosis.

Mass spectrometry-based phosphoproteomics in cancer research

Phosphorylation is one of the most common post translational modifications （PTM）, participating in a large number of processes to regulate cellular functions. Phosphorylation is also one of the key factors in the origin and development of cancer. The rapid development of mass spectrometric-based phosphoproteomic technologies has made it possible for high-throughput identification and quantification of phosphorylation events. In this review, we provide a general introduction and summary of the achievements made in mass spectrometry based phosphoproteomic research, including the approaches for phosphopeptide identification and quantification, as well as instrumentation and data interpretation methods. We also review some discoveries in cancer research made possible by phosphoproteomic analysis technologies.

Adsorptive carbon-based materials for biomedical applications

Adsorption or enrichment has been an indispensable and important measure in biomedical engineering since it is promising in diagnosis and treatment of complex diseases.The ongoing development in this arena starves for exploration of outstanding adsorptive materials.As an excellent candidate for adsorption or enrichment carriers,carbon-based material has demonstrated unique superiority in biomedical arena owing to its integrated charac-teristics.Herein,we review the lasted advance in adsorptive carbon-based materials for biomedical application with emphasis on carbon nanotubes(CNTs)-based,graphene-based,and biomass/polymer-based ones.We begin with the classification of different carbon-based materials and elaborate the respective preparation approaches that are utilized to realize optimized microstructure and physicochemical property.Afterwards,we introduce the different applications of carbon-based materials in biomedical arena,including blood purification,enrichment of glycopeptide and phosphopeptide,and breath analysis.Finally,we present a concise summary and give an outlook of this arena.