de novo sequencing The sequence of peptide/protein is important to study the biological function of the peptide/protein. However, complete characterization of peptides/proteins, including post-translational modifications (PTMs), sequence mutations and variants, is very challenging. There are two approaches to determine the sequence of peptide/protein by mass spectrometry: database search and de novo sequencing. Database search approach compares acquired mass spectra to a database of known protein sequences to identify the protein sequences. De novo sequencing is a process in which amino acid sequences are directly interpreted from tandem mass spectra without the assistance of a database.
 Label-free quantification is a method in mass spectrometry that aims to determine the relative amount of proteins in two or more biological samples. Unlike other methods for protein quantification, label-free quantification does not use a stable isotope containing compound to chemically bind to and thus label the protein.
hERG Safety AssayEdit
Staffed with a group of experts that have gained years of experience in ion channel safety assays and cardiotoxicity assessment, Creative Bioarray offers hERG safety assay in accordance with the ICH S7B guideline to evaluate compound cardiovascular safety and to support drug development. Inhibition assays of other ion channels are also available.
ICH S7B guideline1 regulates in vitro IKr assay (such as hERG safety assay) and in vitro QT assay for identifying and assessing the potential of a test compound to delay ventricular repolarization. Ventricular repolarization is a complex physiological process determined by the duration of the cardiac action potential. It is the net result of the activities of many highly interdependent membrane ion channels and transporters. Many compounds can affect the activities of the ion channels or transporters, thus have the potential of delaying the ventricular repolarization and leading to prolonged QT interval. Creative Bioarray uses the state-of-the-art automated QPatch-HT system to provide a higher-throughput hERG safety assay with better consistency at a lower cost. For small number of compounds or compounds identified with QPatch, we can also perform conventional whole cell patch clamp assay to get detailed mechanistic information. Our GLP level hERG safety assay can provide high quality data for registration purposes. In this assay, CHO-hERG cells or HEK293-hERG cells are used to specifically assess the effect of test compounds on the hERG channel. Pre-compound current and post-compound current are measured by patch clamp, and applied to the calculation of hERG inhibition.
The expertise of our technicians allows us to provide customized assays. We are capable of adjusting the assays according to the detailed requirements of our clients. If you have any special requirements or related questions, please do not hesitate to contact us. Our experts will do their best to assist you.
1, Food, U. S. "Drug Administration (2005). Guidance for industry: ICH S7B nonclinical evaluation of the potential for delayed ventricular repolarization (QT interval prolongation) by human pharmaceuticals." Federal Register 70: 61133-61134. 2, Fermini, Bernard, and Anthony A. Fossa. "The impact of drug-induced QT interval prolongation on drug discovery and development." Nature reviews Drug discovery 2.6 (2003): 439-447. more info on url： https://www.creative-bioarray.com/Services/hERG-Safety.htm
Acetylcholinesterase of Creative EnzymesEdit
Acetylcholinesterase, also known as AChE or acetylhydrolase, is a hydrolase that hydrolyzes the neurotransmitter acetylcholine. AChE is found at mainly neuromuscular junctions and cholinergic brain synapses, where its activity serves to terminate synaptic transmission. It belongs to carboxylesterase family of enzymes. It is the primary target of inhibition by organophosphorus compounds such as nerve agents and pesticides.