The heptapeptide opioids dermorphin and deltophorin in the skin of South American tree frogs contain D-tyrosine and D-alanine.

Alanine:

• An α-amino acid that is used in the biosynthesis of proteins.
• Contains an α-amino group (which is in the protonated form, −NH3+, under biological conditions), an α-carboxylic acid group (which is in the deprotonated form, −COO−, under biological conditions), and a side chain methyl group, making it a nonpolar, aliphatic amino acid.
• Is non-essential in humans: because the body can synthesize it, it does not need to be present in the diet.
• Converts the carbohydrate pyruvate or the breakdown of DNA and the dipeptides carnosine and anserine.
• It is one of the 20 amino acids encoded by the human genetic code and is encoded by all codons starting with GC, namely GCU, GCC, GCA, and GCG.
• The L-isomer of alanine (left-handed) is the one that is incorporated into proteins.
• L-Alanine is second only to leucine in a rate of occurrence, accounting for 7.8% of the primary structure in a sample of 1,150 proteins.
• An important amino acid released by muscle which is used as a major energy source.
• The right-handed form, D-Alanine occurs in polypeptides in some bacterial cell walls and in some peptide antibiotics and occurs in the tissues of many crustaceans and mollusks as an osmolyte.
• Plasma alanine is often decreased when the BCAA (Branched Chain Amino Acids) are deficient, possibly due to muscle metabolism.
• Important in regulating glucose metabolism as alanine levels parallel blood sugar levels in both diabetes and hypoglycemia, and alanine reduces both severe hypoglycemia and the ketosis of diabetes.
• It is an important amino acid for lymphocyte reproduction and immunity.
• Alanine therapy has helped dissolve kidney stones in experimental animals.
• Normal alanine metabolism, like that of other amino acids, is highly dependent upon enzymes that contain vitamin B6.
• Alanine, like GABA, taurine, and glycine, is an inhibitory neurotransmitter in the brain.
• It is produced from pyruvate by transamination.
• It is involved in sugar and acid metabolism, increases immunity and provides energy for muscle tissue, brain, and the central nervous system.
• May relieve symptoms of a type of prostate problem in men called benign prostatic hyperplasia (BPH).

Used for protein synthesis:

• BCAAs are used as a source of energy for muscle cells. During prolonged exercise, BCAAs are released from skeletal muscles and their carbon backbones are used as fuel, while their nitrogen portion is used to form another amino acid, Alanine. Alanine is then converted to Glucose by the liver.
• This form of energy production is called the Alanine-Glucose cycle, and it plays a major role in maintaining the body's blood sugar balance.

Dietary sources:

• Is highly concentrated in meat products and other high-protein foods like wheat germ and cottage cheese.

Biosynthesis:

• Alanine can be synthesized from pyruvate and branched chain amino acids such as valine, leucine, and isoleucine.
• Alanine is most commonly produced by reductive amination of pyruvate, a two-step process.
  1. In the first step, α-ketoglutarate, ammonia and NADH are converted by glutamate dehydrogenase to glutamate, NAD+ and water.
  2. In the second step, the amino group of the newly-formed glutamate is transferred to pyruvate by an aminotransferase enzyme, regenerating the α-ketoglutarate, and converting the pyruvate to alanine.
• The net result is that pyruvate and ammonia are converted to alanine, consuming one reducing equivalent.
• Because transamination reactions are readily reversible and pyruvate is present in all cells, alanine can be easily formed and thus has close links to metabolic pathways such as glycolysis, gluconeogenesis, and the citric acid cycle.

Functions:

• Antioxidant
• Cancer preventive
• Oxidant

Genes:

• AGXT2 SNP rs37369 is located in the coding region of the alanine-glyoxylate aminotransferase-2 gene within chromosome 5 at position 35,072,872. This polymorphism constitutes a nonsynonymous valine-to-isoleucine (V140I) substitution in the AGXT2 protein. rs37369 has been proposed by one study to be the causative SNP of hyper-beta-aminoisobutyric aciduria.

Alanine is Found in These Foods: Organism Concentration (per 100 grams)

• Watercress 27400 ppm
• Horseradish-tree 24930 ppm
• Jute 20840 ppm
• Lambsquarters 20511 ppm
• Carob 19270 ppm
• Soybean 18795 ppm
• Common bean 18710 ppm
• Asparagus 18581 ppm
• Spinach 16864 ppm
• Amaranth 16722 ppm
• Chives 15750 ppm
• Sesame 14802 ppm
• Swamp cabbage 14475 ppm
• White lupine 14470 ppm
• Butternut 14194 ppm
• Adzuki bean 13401 ppm
• Purslane 13400 ppm
• Lentils 13200 ppm
• White mustard 12700 ppm
• Opium poppy 12637 ppm
• Corn 12272 ppm
• Corn salad 12220 ppm
• Lima bean 12190 ppm
• Peanut 12137 ppm
• Yardlong bean 12111 ppm
• Broad bean 12000 ppm
• Lentils 11865 ppm
• Sunflower 11800 ppm
• Hyacinth bean 11775 ppm
• Mung bean 11545 ppm
• Common pea 11353 ppm
• Winged bean 11346 ppm
• Fenugreek 11220 ppm
• Malabar spinach 10870 ppm
• Pigeon pea 10870 ppm
• Cocoa bean 10400 ppm
• Pistachio 10340 ppm
• Common bean 10171 ppm
• Endive 9984 ppm
• Almond 9864 ppm
• Cucurbita (Gourd) 9810 ppm
• Chickpea 9360 ppm
• Lettuce 9333 ppm
• Winged bean 9319 ppm
• Fennel 8655 ppm
• Common bean 8633 ppm
• Chayote 8000 ppm
• Rye 7985 ppm
• Breadfruit 7685 ppm
• Sweet basil 7470 ppm
• Winged bean 7430 ppm
• Sacred lotus 7242 ppm
• Cashew nut 7141 ppm
• Common buckwheat 6880 ppm
• Eggplant 6815 ppm
• Pepper (C. frutescens) 6691 ppm
• Colorado pinyon 6430 ppm
• Common walnut 6320 ppm
• Brazil nut 5897 ppm
• Evening primrose 5870 ppm
• boars 5811 g
• Common pea 5737 ppm
• Potato 5700 ppm
• Mango 5650 ppm
• Cabbage 5615 ppm
• Ginkgo nuts 5352 ppm
• Apricot 4980 ppm
• boars 4900 mg
• Bearded seal 4725 g
• Avocado 4625 ppm
• Cucumber 4557 ppm
• Spirulina 4515 g
• Red beetroot 4338 ppm
• whales 4268 g
• Garden tomato (var.) 4132 ppm
• Oat 4000 ppm
• fish 3799 g
• Whitefish 3780 g
• Sweet orange 3775 ppm
• Common wheat 3542 ppm
• Smelt 3520 g
• Jicama 3500 ppm
• Macadamia nut 3385 ppm
• Sweet potato 3314 ppm
• Soft-necked garlic 3168 ppm
• Whelk 3113 g
• European chestnut 3036 ppm
• Mountain yam 2965 ppm
• Guava 2952 ppm
• Cassava 2765 ppm
• Mandarin orange (Clementine, Tangerine) 2740 ppm
• Sesame 2620 g
• Sacred lotus 2585 ppm
• Jerusalem artichoke 2573 ppm
• Taro 2485 ppm
• Sunflower 2358 g
• Cottonseed 2313 g
• Bison 2250 g
• Fig 2154 ppm
• sheep 2137 g
• Sockeye salmon 2110 g
• Deer 2093 g
• Peanut 2075 g
• Rabbit 1992 g
• turkey 1971 g
• cuttlefish 1964 g
• European plum 1959 ppm
• Deer 1910 g
• Greater sturgeon 1887 g
• birds 1884 g
• Greylag goose 1835 g
• European rabbit 1833 g
• Buffalo 1831 g
• Duck 1825 g
• Chicken (Cock, Hen, Rooster) 1823 g
• Highbush blueberry 1820 ppm
• Northern bluefin tuna 1809 g
• octopus 1804 g
• Ginger 1793 ppm
• Parsley 1778 g
• Thunnus (Common tuna) 1762 g
• European anchovy 1747 g
• Mule deer 1716 g
• Skipjack tuna 1706 g
• Thunnus (Common tuna) 1700 mg
• Safflower 1700 g
• Chicken (Cock, Hen, Rooster) 1700 mg
• Haddock 1700 mg
• Yellowfin tuna 1689 g
• Moose 1686 g
• fish 1655 g
• Beaver 1617 g
• horses 1616 g
• Salmonidae (Salmon, Trout) 1610 g
• Albacore tuna 1605 g
• reindeer 1593 g
• Milkfish 1592 g
• Snapper 1590 g
• Muskrat 1589 g
• Sheepshead 1574 g
• King mackerel 1572 g
• Pink salmon 1570 g
• Chum salmon 1562 g
• Perciformes (Perch-like fishes) 1556 g
• fish 1555 g
• Bluefish 1554 g