Abstract: A system and method for matrix assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry. A method for MALDI-TOF mass spectrometry includes initiating a spectral analysis of a sample on a MALDI-TOF spectrometer. The sample is ionized, and a first ion spectrum is detected and stored. Thereafter, the spectrometer is reset, and the ionizing, detecting, storing, and resetting are repeated until a predetermined plurality of spectra of the sample is acquired.

Abstract: A system and method for matrix assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry. A method for MALDI-TOF mass spectrometry includes initiating a spectral analysis of a sample on a MALDI-TOF spectrometer. The sample is ionized, and a first ion spectrum is detected and stored. Thereafter, the spectrometer is reset, and the ionizing, detecting, storing, and resetting are repeated until a predetermined plurality of spectra of the sample is acquired.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying the optimum probe attachment site. Biosensors are provided having environmentally sensitive dyes that can locate specific biomolecules within living cells and detect chemical and physiological changes in those biomolecules as the living cell is moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, the environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying optimum probe attachment sites. Biosensors are provided having functional molecules that can locate and bind to specific biomolecules within living cells. Biosensors can detect chemical and physiological changes in those biomolecules as living cells are moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, an environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: The invention provides intermediates and methods that allow for site-specific modification of peptides after synthesis. Accordingly, functional molecules can be selectively linked to a peptide to provide a peptide conjugate having altered biological, chemical, or physical properties. For example, functional molecules (e.g. biophysical probes, peptides, polynucleotides, and therapeutic agents) can be linked to a peptide to provide a peptide conjugate having differing and useful properties. The invention also provides a compound of formula (III): wherein: R6 is a peptide; X is a direct bond or a linking group; R7 is hydrogen, (C1-C6)alkyl, an amino protecting group, or a radical comprising one or more aminooxy groups; Y is a direct bond or a linking group; and D is a functional molecule.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying optimum probe attachment sites. Biosensors are provided having functional molecules that can locate and bind to specific biomolecules within living cells. Biosensors can detect chemical and physiological changes in those biomolecules as living cells are moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, an environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: Provided is a system for delivering a liquid sample to an inlet of an analytical instrument. Included is an acoustic ejector driven by a drive system that generates drive signals provided to the ejector. The drive signals are generated with a pulse width sufficient to eject at least a portion of the liquid sample. A reservoir provided for holding the liquid sample is in operational arrangement with the acoustic ejector. A liquid sample voltage source is located within the reservoir, and the liquid sample voltage source is designed to provide a charge to the liquid sample. An analytical instrument voltage source is in operational arrangement with the analytical instrument and is designed to provide a voltage bias between the reservoir and the analytical instrument.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying optimum probe attachment sites. Biosensors are provided having functional molecules that can locate and bind to specific biomolecules within living cells. Biosensors can detect chemical and physiological changes in those biomolecules as living cells are moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, an environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: The invention provides peptide synthons having protected functional groups for attachment of desired moieties (e.g. functional molecules or probes). Also provided are peptide conjugates prepared from such synthons, and synthon and conjugate preparation methods including procedures for identifying the optimum probe attachment site. Biosensors are provided having environmentally sensitive dyes that can locate specific biomolecules within living cells and detect chemical and physiological changes in those biomolecules as the living cell is moving, metabolizing and reacting to its environment. Methods are included for detecting GTP activation of a Rho GTPase protein using polypeptide biosensors. When the biosensor binds GTP-activated Rho GTPase protein, the environmentally sensitive dye emits a signal of a different lifetime, intensity or wavelength than when not bound.

Abstract: Disclosed herein is a process whereby oligopeptides are ligated to form ligation peptide products. In the first step, two starting oligopeptides are ligated to form an intermediate having an amino-thioester linkage. In the second step, the aminothioester linkage undergoes a rearrangement to form a peptide having an N-substituted amide linkage. In an optional third step, the N-substitution of the amide linkage is chemically removed to form a native peptide linkage.