L-proline is a naturally occurring amino acid. It is a columnar crystal at room temperature. It decomposes rapidly when heated to 215-220℃. It is soluble in hot water and ethanol. It is slightly sweet and hygroscopic. It racemizes in alkaline solution. [α]D25-86.5°(water), -60.4°(5N hydrochloric acid). It is distributed in many proteins. It is an amino acid with a moderate content in marine plankton; it also exists in seawater, particulate matter and marine sediments.
Effects and Uses of L-Proline
Effects in Organisms
In organisms, l-proline amino acid is not only an ideal osmotic regulating substance, but also a protective substance for membranes and enzymes and a free radical scavenger, thereby protecting the growth of plants under osmotic stress. For the accumulation of potassium ions in the vacuole, another important osmotic regulating substance in the organism, proline can also regulate the osmotic balance of the cytoplasm.
Industrial Applications
In the synthetic industry, l-proline can participate in inducing asymmetric reactions and can be used as a catalyst for hydrogenation, polymerization, water-mediated reactions, etc. When used as a catalyst for such reactions, it has the characteristics of strong activity and good stereospecificity.
Applications in Other Fields
1. L-proline and its derivatives are usually used as symmetric catalysts in organic reactions. The reduction of CBS and the catalytic aldol condensation reaction of proline are prominent examples.
2. In brewing, proteins are rich in proline combined with polyphenols, which can produce haze (turbidity).
3. Raw materials for the synthesis of bile ester inhibitors.
4. Flavoring agent, when heated with sugar, amino-hydrogen reaction can produce substances with special flavors.
Repair of tooth enamel
According to a recent study by the University of Illinois, the repetition of a simple amino acid in the protein center of tooth enamel makes teeth stronger and more elastic.
In amphibians and animal models, researchers compared the repetition of proline. They found that when the repeats are short, such as in frogs, the teeth will not produce enamel prisms, which are important for the strength of teeth. In contrast, when the protein repeats are longer, they gather a series of molecules to help the enamel crystals grow.
The results of this study were published in the online version of "PLoS Biology" on December 21, 2009. Tom Diekwisch, professor of biology and leader of the study, said that proline repeats are very surprising and are also important for understanding the structure and function of many natural proteins, such as mucins, antifreeze proteins, amyloid proteins, prion proteins, etc.
As enamel grows, it is surrounded by foamy protein blocks. The size of protein bubbles in different animals is also different, ranging from 5 nanometers in cows to 20 nanometers in mice and 40 nanometers in frogs. This finding shows that the longer the proline repeats, the larger the protein bubbles. In addition, the smaller the protein bubbles, the longer the enamel crystals.
Contact Now
