Peptides are strings of amino acids, the building blocks of proteins. Proteins are large molecules that have a wide range of functions in the body, including structural and biochemical processes such as cellular metabolism and gene expression. Peptides are smaller than proteins and have a more fluid structure, making them easier for the body to absorb. This is one of the reasons why peptide supplements are becoming increasingly popular among athletes and people who want to improve their health. The supplements can be taken in the form of pills or topical creams. Several studies indicate that collagen peptides can help improve skin elasticity and reduce signs of aging. Creatine peptides are another popular type of peptide supplement that can increase muscle strength and endurance. The supplements are not regulated by the FDA, so it is important to discuss potential side effects with your doctor before starting a regimen.
A mass spectrometric method for the identification of peptides with molecular masses of up to 1000 daltons. The matrix-assisted laser desorption ionization time of flight (MALDI-TOF) fragmentation technique uses a laser beam to desorb molecules from the sample matrix, resulting in ions that are detected by a mass spectrometer. The instrument then analyzes the ions to determine the chemical structure of the peptide. MALDI-TOF is a highly sensitive and fast method for the identification of peptides.
The Direct Peptide Reactivity Assay (DPRA, OECD test guideline 442C) is an in chemico assay that recapitulates the first key event of the skin sensitization adverse outcome pathway – the interaction of the sensitizing substance with the proteins found on the skin surface. The assay identifies a sensitizer based on its reactivity with synthetic protein peptides containing the nucleophilic residues lysine and cysteine. DPRA has been shown to be reproducible and able to discriminate between peptides with similar structures, making it a good choice for assessing the potency of chemical sensitizers.
Using MALDI-TOF mass spectrometry, a team of scientists at the University of California, Irvine, has developed a method to identify protein complexes in intact cells. The technique uses a combination of microcolumn liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to separate the complexes from their components. MALDI-TOF is able to detect a variety of different protein markers, including the cytoskeletal proteins actin and tubulin, and can be used to identify subcellular locations in single cells. This technology will enable researchers to gain a better understanding of protein function and how they relate to diseases such as neurodegeneration and cancer. It may also be useful for identifying the specific molecule responsible for a particular disease and developing new therapies. direct peptides