High-Performance Sample Substrate of Gold Nanoparticle Multilayers for Surface-Assisted Laser Desorption/Ionization Mass Spectrometry.

The development of a sample substrate with superior performance for desorption and ionization of analyte is the key issue to ameliorate the quality of mass spectra for measurements of small molecules in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). Herein, the homogeneous sample substrate of gold nanoparticle multilayers (AuNPs-ML) with hexagonal lattice was successfully prepared by self-assembly technique. With strong surface plasmon resonance absorption and superior photothermal effect, the sample substrate of AuNPs-ML exhibited high signal sensitivity and low background noise for the detection of model analyte of glucose without additional matrixes in SALDI-MS.

Osteoporosis risk assessment using multilayered gold-nanoparticle thin film via SALDI-MS measurement.

A powerful technique to detect bone biomarkers has been developed for assessment of osteoporosis at the early stage. Two-dimensional multilayered gold-nanoparticle thin film (MTF-AuNPs) was demonstrated as a promising test platform for detection of bone biomarker, hydroxyproline (HYP), measured by surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). With strong surface plasmon resonance and excellent homogeneity, facilely prepared, highly ordered, and large-scale MTF-AuNPs revealed high sensitivity of HYP in the SALDI-MS measurement without additional matrixes, such as α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB).

Enthalpy-driven nuclease-like activity and mechanism of peptide-chlorambucil conjugates.

We report the results of attaching the anticancer drug chlorambucil (CLB) to two high-affinity DNA binding peptides: Met-Hyp-Arg-Lys-(Py)4-Lys-Arg-NH2 (HyM-10) and Gln-Hyp-Arg-Lys-(Py)4-Lys-Arg-NH2 (HyQ-10). These CLB-peptide conjugates cleave DNA very effectively and sequence-selectively without the use of chemicals, heat, or UV irradiation. Polyacrylamide gel electrophoresis identifies the sites where CLB-HyM-10 and CLB-HyQ-10 attack a complementary pair of 5'-(32)P-labeled duplexes derived from pBR322 in the absence of piperidine or other chemical additives.

Discovery of potent antimicrobial peptide analogs of Ixosin-B.

Antimicrobial peptides (AMPs) represent the first defense line against infection when organisms are infected by pathogens. These peptides are generally good targets for the development of antimicrobial agents. Peptide amide analogs of Ixosin-B, an antimicrobial peptide with amino acid sequence of QLKVDLWGTRSGIQPEQHSSGKSDVRRWRSRY, were designed, synthesized and examined for antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

Small nonphosphorylated Grb2-SH2 domain antagonists evaluated by surface plasmon resonance technology.

The growth factor receptor-binding protein-Src homology 2 (Grb2-SH2) domain plays an important role in the oncogenic Ras signal transduction pathway, which involves cell proliferation and differentiation. Therefore, the Grb2-SH2 domain has been chosen as our target for development of potential antiproliferative agents. Herein, we report the study of the inhibitory effects of small nonphosphorylated peptide analogs interacting with the Grb2-SH2 domain protein by surface plasmon resonance (SPR) technology.

Binding potency of peptide fragments of type 1 collagen cross-linked N-telopeptide measured by an enzyme-linked immunosorbant assay.

Osteoporosis represents a major healthcare problem affecting elderly person. Urinary level of the crosslinked N-telopeptide of type I collagen is a sensitive marker of bone resorption. Ten overlapping peptides covering the N-telopeptide of alpha-2 type I collagen were synthesized, purified, and assayed for their relative binding response to anti-type I collagen cross-linked N-telopeptide (NTX) antibody by using a competitive-inhibition enzyme-linked immunosorbent assay (ELISA).