Biochemistry

Advantages and challenges of microfluidic cell culture in polydimethylsiloxane devices
Culture of cells using various microfluidic devices is becoming more common within experimental cell biology. At the same time, a technological radiation of microfluidic cell culture device designs is currently in progress. Ultimately, the utility of microfluidic cell culture will be determined by its capacity to permit new insights into cellular function. Especially insights that would otherwi...


An azide functionalized oligothiophene ligand – a versatile tool for multimodal detection of disease associated protein aggregates
Ligands for identifying protein aggregates are of great interest as such deposits are the pathological hallmark of a wide range of severe diseases including Alzheimer's and Parkinson's disease. Here we report the synthesis of an azide functionalized fluorescent pentameric oligothiophene that can be utilized as a ligand for multimodal detection of disease-associated protein aggregates. The azide...
Evidence of the Direct Involvement of the Substrate TCP Radical in Functional Switching from Oxyferrous O2 Carrier to Ferric Peroxidase in the Dual-Function Hemoglobin/Dehaloperoxidase from Amphitrite ornata
The coelomic O2-binding hemoglobin dehaloperoxidase (DHP) from the sea worm Amphitrite ornata is a dual-function heme protein that also possesses a peroxidase activity. Two different starting oxidation states are required for reversible O2 binding (ferrous) and peroxidase (ferric) activity, bringing into question how DHP manages the two functions. In our previous study, the copresence of substr...


Identification of a Positively Charged Platform in Staphylococcus aureus HtsA That Is Essential for Ferric Staphyloferrin A Transport
In response to iron starvation, Staphylococcus aureus secretes both staphyloferrin A and staphyloferrin B, which are high-affinity iron-chelating molecules. The structures of both HtsA and SirA, the ferric-staphyloferrin A [Fe(III)-SA] and ferric-staphyloferrin B [Fe(III)-SB] receptors, respectively, have recently been determined. The structure of HtsA identifies a novel form of ligand entrapme...
Dynamic profile and adipogenic role of growth differentiation factor 5 (GDF 5) in the differentiation of 3T3-L1 preadipocytes
Adipocyte differentiation is key to determining the number of adipocytes during the development of obesity. Recent studies have shown that growth differentiation factor-5 (GDF5) promotes brown adipogenesis, however its role in white adipogenesis is still uncertain. The aim of the present study was to investigate the effect of GDF5 on white adipogenesis using 3T3-L1 preadipocyte model. In the pr...


Solvent-Assisted Orientation of Poly(3-hexylthiophene)-Functionalized CdSe Nanorods Under an Electric Field
The synthesis of high-aspect-ratio (AR) CdSe (NRs) nanorods and their ordered assembly over large areas are reported. Long-range ordering of hexagonal arrays of high-AR NRs is achieved by a combination of controlled solvent evaporation and the use of an applied electric field. Vertically oriented assemblies of CdSe NRs functionalized with oligo- and polythiophene are also obtained. Aligned and ...
Tandem Action of SNS–Cr and CGC–Ti in Preparation of Ethylene–1-Hexene Copolymers from Ethylene Feedstock
Ethylene–1-hexene copolymer materials, ranging from semicrystalline linear low-density poly­ethylene (LLDPE) to completely amorphous polyethylenes (PEs), are prepared from ethylene alone in a single reactor by the tandem polymerization of bis(2-dodecylsulfanyl-ethyl)amine–CrCl3 (SNS–Cr) and (N-tert-butylamido) (tetramethylcyclopentadienyl)–titanium dichloride (CGC–Ti) at 75 °C and u...

Paenilarvins: Iturin Family Lipopeptides from the Honey Bee Pathogen Paenibacillus larvae
The bacterium Paenibacillus larvae has been extensively studied as it is an appalling honey bee pathogen. In the present work, we screened crude extracts derived from fermentations of P. larvae genotypes ERIC I and II for antimicrobial activity, following the detection of four putative secondary metabolite gene clusters that show high sequence homology to known biosynthetic gene clusters for th...
Use of Copy Number Deletion Polymorphisms to Assess DNA Chimerism
We describe a novel approach that harnesses the ubiquity of copy number deletion polymorphisms in human genomes to definitively detect and quantify chimeric DNA in clinical samples. Unlike other molecular approaches to chimerism analysis, the copy number deletion (CND) method targets genomic loci (>50 base pairs in length) that are wholly absent from wild-type (i.e., self) background DNA sequen...

Revision of the Troponin T Release Mechanism from Damaged Human Myocardium
Cardiac troponin T (cTnT) is released from damaged heart tissue in patients with acute myocardial infarction. It is presumed that most cTnT is tightly bound and released following the degradation of myofibrils in necrotic cardiomyocytes, resulting in sustained increases in circulating cTnT. Evidence of a large irreversibly bound fraction is based on the inability to extract most cTnT from cardi...
Immunoextraction-Tandem Mass Spectrometry Method for Measuring Intact Human Chorionic Gonadotropin, Free beta-Subunit, and beta-Subunit Core Fragment in Urine
Human chorionic gonadotropin (hCG) stimulates testosterone production by the testicles. Because of the potential for abuse, hCG is banned (males only) in most sports and has been placed on the World Anti-Doping Agency list of prohibited substances. Intact hCG, free β-subunit (hCGβ), and β-subunit core fragment (hCGβcf) are the major variants or isoforms in urine. Immunoassay...

Quantification of Serum IgG Subclasses by Use of Subclass-Specific Tryptic Peptides and Liquid Chromatography-Tandem Mass Spectrometry
Measurement of IgG subclasses is a useful tool for investigation of humoral immune deficiency in the presence of total IgG within reference intervals and IgG4-related disease. Nephelometry has been the method of choice for quantification. We describe an LC-MS/MS method that can multiplex all 4 subclasses along with total IgG by use of either IgG subclass-specific peptide stable isotope–la...
Utilization of Assay Performance Characteristics to Estimate Hemoglobin A1c Result Reliability
Allowable total error (TEa) goals for hemoglobin (Hb) A1c require minimal assay imprecision and bias and implementation of a robust QC monitoring program. Here, we compare the combined influence on the risk of reporting unreliable results of TEa goals, a routine QC practice, and assay performance characteristics of 6 Hb A1c instruments across 4 academic medical centers. The CLSI protocols EP-5 ...
Peptidomics of Urine and Other Biofluids for Cancer Diagnostics
Cancer is a leading cause of death worldwide. The low diagnostic sensitivity and specificity of most current cancer biomarkers make early cancer diagnosis a challenging task. The comprehensive study of peptides and small proteins in a living system, known as "peptidomics," represents an alternative technological approach to the discovery of potential biomarkers for the assessment of a wide vari...
Three of 7 Hemoglobin A1c Point-of-Care Instruments Do Not Meet Generally Accepted Analytical Performance Criteria
In 2009, we investigated the conformance of 8 hemoglobin A1c (Hb A1c) point-of-care (POC) instruments. Since then, instruments have improved and new devices are available on the market. In this second study, we evaluated the performance of DCA Vantage, Afinion, InnovaStar, Quo-Lab, Quo-Test, Cobas B101, and B-analyst Hb A1c POC instruments. Clinical and Laboratory Standards Institute protocols ...