40 research outputs found
The Application of Nanoparticles of Waste Tires in Remediating Boron from Desalinated Water
A waste tire rubber (WTR) collected from the remains discarded tires has exhibited a noteworthy capacity to adsorb Boron. In the current study, the boron adsorption remediation from water at selected pH values, initial boron concentration, contact time, adsorbent dosage and particle size were examined using the WTR, the chemically modified WTR, and nano-WTR. The adsorption isotherms were best fitted to the Freundlich model with a high correlation coefficient (R2 :0.89-0.99), while the adsorption kinetics were satisfactorily described by the pseudo second order kinetic equation with correlation coefficient (R2: 1).The boron remediation using the WTR, the chemically modified-WTR and nano-WTR at low boron concentration (≤ 17.7 mg/L) were comparable with other adsorbents. The highest adsorption capacities for WTR, chemically modified-WTR and nano-WTR at initial concentration of 17.5 mg/L were 16.7 ± 1.3 mg/g, 13.8 ± 1.9 mg/g and 12.7 ± 1.8mg/g, respectively.This publication was made possible by UREP # (19-171-1-031) from the Qatar National
Research Fund (a member of Qatar Foundation)
LC–MS/MS Identification of the O‑Glycosylation and Hydroxylation of Amino Acid Residues of Collagen α‑1 (II) chain from Bovine Cartilage
O-Glycosylation
of collagen is a unique type of posttranslational
modifications (PTMs) involving the attachment of galactose (Gal) or
glucose-galactose (Glc-Gal) moieties to hydroxylysine (HyK). Also,
hydroxyproline (HyP) result from the posttranslational hydroxylation
of some proline residues in collagen. Here, LC–MS/MS was effectively
employed to identify 23 O-glycosylation sites and a large number of
HyP residues associated with bovine type II collagen α-1 chain
(CO2A1). The modifications of the 23 O-glycosylation sites varied
qualitatively and quantitatively. Both Gal and Glc-Gal moieties occupied
22 of the identified glycosylation sites, while K773 was observed
as unmodified. A large number of HyP residues at Yaa positions of
Gly-Xaa-Yaa motif were detected. HyP residues at Xaa positions of
Gly-HyP-HyP, Gly-HyP-Ala, and Gly-HyP-Val motifs were also observed.
Notably, HyP residue of Gly-HyP-Gln motif was detected, which has
not been previously reported. Moreover, the deamidation of 8 Asn residues
was identified, of which 2 Asp residues were observed at different
retention times because of isomerization (Asp vs isoAsp). Partial
macroheterogeneities of some CO2A1 glycosylation sites were revealed
by LC–MS/MS analysis. ETD experiments revealed partial macroheterogeneities
associated with K299–K308, K452–K464, K464–K470,
and K857–K884 glycosylation sites. Semiquantitative data suggest
that the glycosylation of hydroxylysine residues is site-specific
LC–MS/MS Identification of the O‑Glycosylation and Hydroxylation of Amino Acid Residues of Collagen α‑1 (II) chain from Bovine Cartilage
O-Glycosylation
of collagen is a unique type of posttranslational
modifications (PTMs) involving the attachment of galactose (Gal) or
glucose-galactose (Glc-Gal) moieties to hydroxylysine (HyK). Also,
hydroxyproline (HyP) result from the posttranslational hydroxylation
of some proline residues in collagen. Here, LC–MS/MS was effectively
employed to identify 23 O-glycosylation sites and a large number of
HyP residues associated with bovine type II collagen α-1 chain
(CO2A1). The modifications of the 23 O-glycosylation sites varied
qualitatively and quantitatively. Both Gal and Glc-Gal moieties occupied
22 of the identified glycosylation sites, while K773 was observed
as unmodified. A large number of HyP residues at Yaa positions of
Gly-Xaa-Yaa motif were detected. HyP residues at Xaa positions of
Gly-HyP-HyP, Gly-HyP-Ala, and Gly-HyP-Val motifs were also observed.
Notably, HyP residue of Gly-HyP-Gln motif was detected, which has
not been previously reported. Moreover, the deamidation of 8 Asn residues
was identified, of which 2 Asp residues were observed at different
retention times because of isomerization (Asp vs isoAsp). Partial
macroheterogeneities of some CO2A1 glycosylation sites were revealed
by LC–MS/MS analysis. ETD experiments revealed partial macroheterogeneities
associated with K299–K308, K452–K464, K464–K470,
and K857–K884 glycosylation sites. Semiquantitative data suggest
that the glycosylation of hydroxylysine residues is site-specific
LC–MS/MS Identification of the O‑Glycosylation and Hydroxylation of Amino Acid Residues of Collagen α‑1 (II) chain from Bovine Cartilage
O-Glycosylation
of collagen is a unique type of posttranslational
modifications (PTMs) involving the attachment of galactose (Gal) or
glucose-galactose (Glc-Gal) moieties to hydroxylysine (HyK). Also,
hydroxyproline (HyP) result from the posttranslational hydroxylation
of some proline residues in collagen. Here, LC–MS/MS was effectively
employed to identify 23 O-glycosylation sites and a large number of
HyP residues associated with bovine type II collagen α-1 chain
(CO2A1). The modifications of the 23 O-glycosylation sites varied
qualitatively and quantitatively. Both Gal and Glc-Gal moieties occupied
22 of the identified glycosylation sites, while K773 was observed
as unmodified. A large number of HyP residues at Yaa positions of
Gly-Xaa-Yaa motif were detected. HyP residues at Xaa positions of
Gly-HyP-HyP, Gly-HyP-Ala, and Gly-HyP-Val motifs were also observed.
Notably, HyP residue of Gly-HyP-Gln motif was detected, which has
not been previously reported. Moreover, the deamidation of 8 Asn residues
was identified, of which 2 Asp residues were observed at different
retention times because of isomerization (Asp vs isoAsp). Partial
macroheterogeneities of some CO2A1 glycosylation sites were revealed
by LC–MS/MS analysis. ETD experiments revealed partial macroheterogeneities
associated with K299–K308, K452–K464, K464–K470,
and K857–K884 glycosylation sites. Semiquantitative data suggest
that the glycosylation of hydroxylysine residues is site-specific
Fast and Efficient Online Release of N‑Glycans from Glycoproteins Facilitating Liquid Chromatography–Tandem Mass Spectrometry Glycomic Profiling
A novel online enzyme reactor incorporating peptide-N-glycosidase
F (PNGase F) on a monolithic polymer support has been developed to
allow the rapid simultaneous release of both neutral and acidic N-linked
glycans from glycoproteins. The PNGase F monolithic reactor was fabricated
in a fused silica using glycidyl methacrylate-<i>co</i>-ethylene
dimethacrylate polymer. The reactor was coupled to a C8 trap and a
porous graphitic carbon (PGC) HPLC-chip. This arrangement was interfaced
to an ion trap mass spectrometer for liquid chromatography–mass
spectrometry (LC–MS) and liquid chromatography–tandem
mass spectrometry (LC–MS/MS) analyses. The performance of the
PNGase F reactor was optimized using the MS signal for the disialylated
biantennary N-glycan derived from fetuin. Optimum conditions for glycan
release were attained at room temperature using a loading flow rate
of 2 μL/min and a reaction time of 6 min. The loading capacity
of the reactor was determined to be around 2 pmol of glycoprotein.
The online digestion and MS characterization experiments resulted
in sensitivities as high as 100 fmol of glycoprotein and 0.1 μL
of human blood serum. The enzyme reactor activity was also shown to
remain stable after 1 month of continuous use. Both small and large
glycoproteins as well as glycoproteins containing high-mannose glycans,
fucolsylated glycans, sialylated glycans, and hybrid structures were
studied. The model glycoproteins included ribonuclease B, fetuin,
α<sub>1</sub>-acid glycoprotein, immunoglobulin, and thyroglobulin.
All N-glycans associated with these model glycoproteins were detected
using the online PNGase F reactor setup
LC–MS/MS Quantitation of Esophagus Disease Blood Serum Glycoproteins by Enrichment with Hydrazide Chemistry and Lectin Affinity Chromatography
Changes
in glycosylation have been shown to have a profound correlation
with development/malignancy in many cancer types. Currently, two major
enrichment techniques have been widely applied in glycoproteomics,
namely, lectin affinity chromatography (LAC)-based and hydrazide chemistry
(HC)-based enrichments. Here we report the LC–MS/MS quantitative
analyses of human blood serum glycoproteins and glycopeptides associated
with esophageal diseases by LAC- and HC-based enrichment. The separate
and complementary qualitative and quantitative data analyses of protein
glycosylation were performed using both enrichment techniques. Chemometric
and statistical evaluations, PCA plots, or ANOVA test, respectively,
were employed to determine and confirm candidate cancer-associated
glycoprotein/glycopeptide biomarkers. Out of 139, 59 common glycoproteins
(42% overlap) were observed in both enrichment techniques. This overlap
is very similar to previously published studies. The quantitation
and evaluation of significantly changed glycoproteins/glycopeptides
are complementary between LAC and HC enrichments. LC–ESI–MS/MS
analyses indicated that 7 glycoproteins enriched by LAC and 11 glycoproteins
enriched by HC showed significantly different abundances between disease-free
and disease cohorts. Multiple reaction monitoring quantitation resulted
in 13 glycopeptides by LAC enrichment and 10 glycosylation sites by
HC enrichment to be statistically different among disease cohorts
Isomeric Separation of α2,3/α2,6-Linked 2‑Aminobenzamide (2AB)-Labeled Sialoglycopeptides by C18-LC-MS/MS
Determination of the relative expression levels of the
α2,3/α2,6-sialic
acid linkage isomers on glycoproteins is critical to the analysis
of various human diseases such as cancer, inflammation, and viral
infection. However, it remains a challenge to separate and differentiate
site-specific linkage isomers at the glycopeptide level. Some derivatization
methods on the carboxyl group of sialic acid have been developed to
generate mass differences between linkage isomers. In this study,
we utilized chemical derivatization that occurred on the vicinal diol
of sialic acid to separate linkage isomers on a reverse-phase column
using a relatively short time. 2-Aminobenzamide (2AB) labeling derivatization,
including periodate oxidation and reductive amination, took only ∼3
h and achieved high labeling efficiency (>90%). Within a 66 min
gradient,
the sialic acid linkage isomers of 2AB-labeled glycopeptides from
model glycoproteins can be efficiently resolved compared to native
glycopeptides. Two different methods, neuraminidase digestion and
higher-energy collision dissociation tandem mass spectrometry (HCD-MS2) fragmentation, were utilized to differentiate those isomeric
peaks. By calculating the diagnostic oxonium ion ratio of Gal2ABNeuAc
and 2ABNeuAc fragments, significant differences in chromatographic
retention times and in mass spectral peak abundances were observed
between linkage isomers. Their corresponding MS2 PCA plots
also helped to elucidate the linkage information. This method was
successfully applied to human blood serum. A total of 514 2AB-labeled
glycopeptide structures, including 152 sets of isomers, were identified,
proving the applicability of this method in linkage-specific structural
characterization and relative quantification of sialic acid isomers
Isomeric Separation of α2,3/α2,6-Linked 2‑Aminobenzamide (2AB)-Labeled Sialoglycopeptides by C18-LC-MS/MS
Determination of the relative expression levels of the
α2,3/α2,6-sialic
acid linkage isomers on glycoproteins is critical to the analysis
of various human diseases such as cancer, inflammation, and viral
infection. However, it remains a challenge to separate and differentiate
site-specific linkage isomers at the glycopeptide level. Some derivatization
methods on the carboxyl group of sialic acid have been developed to
generate mass differences between linkage isomers. In this study,
we utilized chemical derivatization that occurred on the vicinal diol
of sialic acid to separate linkage isomers on a reverse-phase column
using a relatively short time. 2-Aminobenzamide (2AB) labeling derivatization,
including periodate oxidation and reductive amination, took only ∼3
h and achieved high labeling efficiency (>90%). Within a 66 min
gradient,
the sialic acid linkage isomers of 2AB-labeled glycopeptides from
model glycoproteins can be efficiently resolved compared to native
glycopeptides. Two different methods, neuraminidase digestion and
higher-energy collision dissociation tandem mass spectrometry (HCD-MS2) fragmentation, were utilized to differentiate those isomeric
peaks. By calculating the diagnostic oxonium ion ratio of Gal2ABNeuAc
and 2ABNeuAc fragments, significant differences in chromatographic
retention times and in mass spectral peak abundances were observed
between linkage isomers. Their corresponding MS2 PCA plots
also helped to elucidate the linkage information. This method was
successfully applied to human blood serum. A total of 514 2AB-labeled
glycopeptide structures, including 152 sets of isomers, were identified,
proving the applicability of this method in linkage-specific structural
characterization and relative quantification of sialic acid isomers
Glycoproteomics: Identifying the Glycosylation of Prostate Specific Antigen at Normal and High Isoelectric Points by LC–MS/MS
Prostate
specific antigen (PSA) is currently used as a biomarker
to diagnose prostate cancer. PSA testing has been widely used to detect
and screen prostate cancer. However, in the diagnostic gray zone,
the PSA test does not clearly distinguish between benign prostate
hypertrophy and prostate cancer due to their overlap. To develop more
specific and sensitive candidate biomarkers for prostate cancer, an
in-depth understanding of the biochemical characteristics of PSA (such
as glycosylation) is needed. PSA has a single glycosylation site at
Asn69, with glycans constituting approximately 8% of the protein by
weight. Here, we report the comprehensive identification and quantitation
of N-glycans from two PSA isoforms using LC–MS/MS. There were
56 N-glycans associated with PSA, whereas 57 N-glycans were observed
in the case of the PSA-high isoelectric point (pI) isoform (PSAH).
Three sulfated/phosphorylated glycopeptides were detected, the identification
of which was supported by tandem MS data. One of these sulfated/phosphorylated
N-glycans, HexNAc5Hex4dHex1s/p1 was identified in both PSA and PSAH
at relative intensities of 0.52 and 0.28%, respectively. Quantitatively,
the variations were monitored between these two isoforms. Because
we were one of the laboratories participating in the 2012 ABRF Glycoprotein
Research Group (gPRG) study, those results were compared to that presented
in this study. Our qualitative and quantitative results summarized
here were comparable to those that were summarized in the interlaboratory
study
Glycomic Profiling of Tissue Sections by LC-MS
Because routine preparation of glycan
samples involves multiple
reaction and cleaning steps at which sample loss occurs, glycan analysis
is typically performed using large tissue samples. This type of analysis
yields no detailed molecular spatial information and requires special
care to maintain proper storage and shipping conditions. We describe
here a new glycan sample preparation protocol using minimized sample
preparation steps and optimized procedures. Tissue sections and spotted
samples first undergo on-surface enzymatic digestion to release N-glycans.
The released glycans are then reduced and permethylated prior to online
purification and LC-electrospray ionization (ESI)-MS analysis. The
efficiency of this protocol was initially evaluated using model glycoproteins
and human blood serum (HBS) spotted on glass or Teflon slides. The
new protocol permitted the detection of permethylated N-glycans derived
from 10 ng RNase B. On the other hand, 66 N-glycans were identified
when injecting the equivalent of permethylated glycans derived from
a 0.1-μL aliquot of HBS. On-tissue enzymatic digestion of nude
mouse brain tissue permitted the detection of 43 N-glycans. The relative
peak areas of these 43 glycans were comparable to those from a C57BL/6
mouse reported by the Consortium for Functional Glycomics (CFG). However,
the sample size analyzed in the protocol described here was substantially
smaller than for the routine method (submicrogram vs mg). The on-tissue
N-glycan profiling method permits high sensitivity and reproducibility
and can be widely applied to assess the spatial distribution of glycans
associated with tissue sections, and may be correlated with immunoflourescence
imaging when adjacent tissue sections are analyzed