α cyano 4 hydroxycinnamic acid hcca

Thawed saliva and gingival fluid samples were vortexed. Subsequently, 1 µL of sample was spotted onto a MALDI MTP 384 target plate of polished steel (Bruker Daltonics GmbH, Germany). The air-dried sample was covered with 1 µL of matrix solution: α-cyano-4-hydroxycinnamic acid (HCCA) (Sigma Aldrich, St Louis, MO, USA) diluted in acetonitrile/water, 1:1, v/v with 2.5% TFA (Sigma-Aldrich, St. Louis, MO, USA).

Methanol (99.8%), Ethanol (99.8%), dichoromethane (99.8%), acetonitrile (ACN) (99.8%), N-dimethylformamide (99.8%), piperidine (99.5% biotech. grade), hexamethyldisilazane (HMDS) (99%), osmium tetraoxide (4%), parafomraldehyde (36%), gluteraldehyde (8%), N-diisopropylethylamine (99.5% biotech. grade), 1-cyano-2-ethoxy-2-oxoethylidenaminooxy dimethylamino-morpholino-carbenium hexafluorophosphate (COMU) (97%), triisopropylsilane (99%), trifluoroacetic acid (TFA) (99%), α-cyano-4-hydroxycinnamic acid (HCCA) were acquired from Sigma (Oakville, ON, Canada) and used without further purification. Fmoc amino acids and wang resins were purchased from ChemPep (Wellington, FL, USA). Active human recombinant MMP-2 was acquired from EMD Millipore (Etobicoke, ON, Canada). Uranyl acetate and TEM grids were obtained from Ted Pella Inc. (Redding, CA, USA).

OymaPure,
Arg(Pbf)-OH, Fmoc-Gly-OH, Fmoc-Asp(OtBu)-OH,
Fmoc-Cys(Trt)-OH Fmoc-Lys(Boc)-OH, Fmoc-Phe-OH, Fmoc-Gln(Trt)-OH,
and Fmoc-Phe-Wang resin were purchased from Novabiochem. N-Ethyldiisopropylamine (DIPEA), piperidine (≥99.5% for peptide
synthesis), and trifluoroacetic acid (TFA, ≥99.9%) were obtained
from Carl Roth. Dimethylformamide (DMF for peptide synthesis), diethyl
ether, and dimethyl sulfoxide (DMSO, ≥99.97+%) were purchased
from Acros Organics. Acetonitrile (HPLC grade) was purchased from
Fisher Scientific. Syringe filters Minisart SRP (0.20 μm) were
obtained from Sartorius. Glass coverslips (24 × 50 mm) were obtained
from Hirschmann and Glass coverslips (Ø = 13 mm) were purchased
from Fisher Scientific. ITO-coated glass slides for scanning electron
microscope (SEM) (15 × 20 mm) were obtained from Ossila and for
MALDI-MSI (25 × 75 mm) were purchased from Bruker Daltonics.
LE Agarose was obtained from Biozym Scientific. A549 cells, Dulbecco’s
Modified Eagle’s Medium (DMEM, 4.5 g/L glucose/glutamine),
penicillin/streptavidin, fetal bovine serum (FBS), and minimum essential
medium non-essential amino acids (MEM NEAA, 100×) were purchased
from Thermo Fisher Scientific. The ProteoStat Amyloid Plaque detection
Kit was purchased from Enzo Life Sciences, Inc. α-Cyano-4-hydroxycinnamic
acid (HCCA) was purchased from Sigma-Aldrich.

Water LC–MS Chromasolv, ethanol, acetonitrile, trifluoroacetic acid, formic acid, and isopropanol were obtained from Sigma Aldrich (Steinheim, Germany). Chloroform was purchased from POCH (Poland), while ultrapure water was obtained with the Milli-Q water system purchased from Millipore (Bedford, MA, USA). All chemicals needed for the MALDI-MS analysis (with the highest available purity) were purchased from Fluka Feinchemikalien GmbH (part of Sigma Aldrich). α-Cyano-4-hydroxycinnamic acid (HCCA) was obtained from Sigma Aldrich (St. Louis, MO, USA) and used as a matrix for the MALDI analysis. Sample decomposition was carried out using polished steel targets (Bruker Daltonik). External calibration was performed using protein Calibration Standards I (Bruker Daltonik, Bremen, Germany). Standards of L-phosphatidylcholine (≥99%) (PC), L-phosphatidylethanolamine (≥98%) (PE), sphingomyelin (SM) (≥95%), L-lysophosphatidylcholine (≥98%) (LPC), L-lysophosphatidylethanolamine (≥97%) (LPE), L-phosphatidylglycerol (≥98%) (PG), L-lysophosphatidylglycerol (≥98%) (LPG), L-phosphatidylinositol (≥98%) (PI), L-lysophosphatidylinositol (≥98%) (LPI), phosphatidic acid (≥98%) (PA), and lysophosphatidic acid (≥98%) (LPA) from egg yolk were purchased from Larodan Lipids (Malmö, Sweden).