酪氨酸.

Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in cheese, 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells to synthesize proteins. It has a phenol side chain with a hydroxyl group. Upon the location of the hydroxyl group, there are three structural isomers of Tyr, namely para-Tyr (p-Tyr), meta-Tyr (m-Tyr) and ortho-Tyr (o-Tyr). Enzymatically, only the first isomer (p-Tyr) is produced from L-Phe by the Phe-hydroxylase enzyme. The other two isoforms, m-Tyr and o-Tyr can be produced as a consequence of free radical attack on Phe in states with increased oxidative stress.

 

Tyrosine is converted to DOPA by tyrosine hydroxylase, an enzyme.

Some of the tyrosine residues can be tagged with a phosphate group (phosphorylated) by protein kinases. (In its phosphorylated state, it is referred to as phosphotyrosine.). Tyrosine phosphorylation is considered as one of the key steps in signal transduction and regulation of enzymatic activity. Phosphotyrosine can be detected through specific antibodies. Tyrosine residues may also be modified by the addition of a sulfate group, a process known as tyrosine sulfation. Tyrosine sulfation is catalyzed by tyrosylprotein sulfotransferase (TPST). Like the phosphotyrosine antibodies mentioned above, antibodies have recently been described that specifically detect sulfotyrosine. Tyrosine is also precursor to the thyroid hormones thyroxine and triiodothyronine, the pigment melanin, and the biologically-active catecholamines dopamine, norepinephrine and epinephrine.

In Papaver somniferum, the opium poppy, it is used to produce morphi

 

Biosynthesis

Tyrosine cannot be completely synthesized by animals, although it can be made by hydroxylation of phenylalanine if the latter is in abundant supply. It is produced by plants and most microorganisms from prephenate, an intermediate on the shikimate pathway.

Prephenate is oxidatively decarboxylated with retention of the hydroxyl group to give p-hydroxyphenylpyruvate. This is transaminated using glutamate as the nitrogen source to give tyrosine and α-ketoglutarate.

Tyrosine hydroxylase

Tyrosine hydroxylase (TH) is the rate-limiting enzyme involved in the synthesis of the catecholamines such as dopamine, norepinephrine and epinephrine.

 

Medical use

L-Tyrosine is sometimes recommended by practitioners as helpful for weight loss, clinical depression, Parkinson's Disease , and phenylketonuria; however, one study found that it had no impact on endurance exercise performance.

  

If the human body lacks of the Lao ammonia sour

 【White eclipse(vitiligo) 】

The white eclipse and then white Dian breeze is a kind of cause of disease didn't the completely explicit acquired dye lack of a disease.yet

 

Most scholars think the occurrence of that disease is due to Lao  inside the melanin cell of of the epidermis and leatherThe system function decrease or lose, cause the partial melanin cell decrease or lose activity, the thus born melanin measures reduce and causes.

 

【The cause of disease of the white eclipse 】

The white eclipse is a kind of disease with complicated cause of disease.It is concrete with the result that cause because of with outbreak the mechanism haven't yet been completely explicit currently.Possible and various factor the comprehensive function is relevant.As for the reason and mechanism that the white eclipse sufferer loses melanin mainly have a few theories as follows:

 

(A)Immunity theory:The scholar thinks the white eclipse is an autoimmune sex disease

(Two)The melanin cell from ruin theory:The experiment proves some chemistry materials to have the breakage function of the selectivity to the melanin cell, making the skin take off a color thus.

(Three)Nerve chemistry factor theory:The melanin cell originates the nerve ridge, white eclipse sufferer's skin Sun sometimes the anti- skin stanza distribute.The occurrence that therefore thinks white Dian breeze has something to do with the nerve chemistry factor.

(Four)The material lacks of or excess theory:

● The zinc, calcium, the magnesium ion lacks of

● Become the raw material-benzene C ammonia of the melanin sour is sour to lack of with the Lao ammonia

● The copper ion lacks of

● The vitamin C absorbs excess

(Five)Spirit factor theory:When spirit is nervous, the sympathetic nerves is excited, having another Ba to lead to adrenal glands namely to synthesize at least, as a result the melanin synthesizes to repress necessarily.

(Six)Induct factor theory

● The sunlight insolates

● Get in touch with the compound of Fen Ji

 

【The condition of illness of the white eclipse 】

The pathological changes presents the solid white color circular or takes off to lose a spot irregularly, the surface is smooth, the boundary is clear, the edge dye increases.Skin become white to sunlight more normal skin sensitive, take a sunbathe slightly namely flush.The course of illness passes by slow-moving, gradually to on all sides extension, stop spreading while blending or reaching certain degree each other, the Li is long constantly.Occurrence the white eclipse in face, its outbreak time is short, the area is small, if canned get to cure in early days, the curative effect was better, so cured in early days to pass importance.

 

【The treatment of the white eclipse 】

The white eclipse is a kind of more unprogressive chronic disease, needing to be treated hard.First, the spirit wants to be optimistic, the mood wants to be relaxed, absolutely not to pessimism and anxious, relieve all otiose thoughts concern.Because worried, fear, pessimism etc. motion, will influence the nerve function, to this disease is harmful not beneficial, cure to have a longer process, need persistent.

 

The food is also many problems that the sufferer concerns.Much proper eat some enrich to contain the Lao ammonia sour are material with copper, zinc, iron...etc. of food, as the lean meat, egg, various vegetable with fresh animal internal organs, milk, vegetable sponge, eggplant, carrot...etc. and bean ware etc..

 

The ultraviolet ray in the sunlight can promote the melanin metabolize, so the adequacy takes a sunbathe, the dialogue Dian breeze contain certain treatment function.But in blazing hot summer, the ultraviolet ray in the sunlight is anti- to repress the metabolism of the melanin, the disadvantage synthesizes in the melanin, so should avoid.

 

The treatment method of the white eclipse is a lot of, can apply the medicine part to draw outside, or combine internal medicine.

 

Use medicine,such as white spot Ding, black plum Ding, the sulphur mercury white spot Cha...etc., outside.The internal medicine should press the everyone different condition of illness dialectical to cure.

 

The white eclipse is the dye in the skin to disappear, usually the dye of the skin by a kind of dye cell secrete, and at white eclipse sufferer, the skin then disappears such kind of cell, its right reason isn't clear, may have heredity Qing to.May spread slowly, and can't be certain while suffering from white eclipse when just would be stop spread of, the luckily white eclipse removes ream infected part to disappear the outside of the dye, will not have any influence to the body, no matter infected part have much big, or spread how widely smooth, also have no influence to the healthy body.

 

The white eclipse also allows of no an easy treatment, having no medicine can accurate cure white eclipse, the method shines on sun lamp after drawing a medicine or taking a medicine mostly now, want to be handled by the skin specialty doctor. The one who suffer from white eclipse can go to the skin specialty clinic of the government to beg Zhen, can go to the madam's health hospital of the gulf Zi shell to see the skin specialty in the harbor island, seeing a skin specialty in nine dragons can go to the oil Ma ground cannon set street horse the consultation.As for report a chapter last and all medicine advertisements all not dependable, because of absolutely being not published by formal doctor, as far as report the chapter advertisement that declares to cure white eclipse up, then believe more absolutely not to.

The white eclipse didn't need to quit, because the white eclipse and any food all relate to in no way.

The L-Lao ammonia is sour to belong to not- essential amino acids.The Lao ammonia the sour matter body constitute of protein rather important composition.It can also produce to appear lost in thought through conduct vegetable, if left Xuan many Ba, many Ba's ammonia, positive adrenaline, and adrenaline.Many milks product, the meat, fish, wheat, oats and the containment Lao ammonia sour protein food in.The L-Lao ammonia is sour to still do good cancellation worry anxiously, melancholy, allergy, headache etc. the treatment of the disease.It can help the function that the manufacturing and help adrenal glands, thyroid gland and brain of the melanin(the dye of the skin and hair) descend gland.

 

The person who has the inborn benzene Tong urine disease can't metabolize the benzene C ammonia sour.Will produce the intelligence obstacle and heavy disabled.Take the benzene C ammonia sour can prevent this type of problem.And then the day lacks of the Lao ammonia sour will also cause the benzene Tong urine disease, have to depend on the complement Lao ammonia is sour to deal with the benzene Tong urine disease.In addition to being the precursor of the positive adrenaline, the L-Lao ammonia is sour to be also used for synthesizing the adrenaline and many Ba's ammonias.It can be used to give out a drug addiction.The Lao ammonia is sour and can change the melanin of the skin and dark sink, resist harmful ultraviolet ray to the human body.The Lao ammonia is sour to also constitute plain important composition of thyroid gland.

 

The melanin formation reason

The familiar melanin formation reason, widespread cognition is usually project light upon a sun cause of spot problem, for example black spot, freckle.But in fact, the formation of the melanin be also likely to be factor of the inborn constitution heredity, perhaps is the endocrine function occurrence variety cause of problem condition.

 

Other born reason still includes:

1.The pituitary gland secretes the function that the melanin cell stimulates a vegetable to build up

2.The live increment of the Lao ammonia sour An

3.The ultraviolet ray projects light upon, the Lao ammonia is sour to take place to oxidize reaction easily

4.The age increases, the free radicals increment inside the body waits for

5.Use not appropriate cosmetics

 

What is the melanin

The color spot in our skin is a kind that belongs to the dye obstacle skin disease on the skin section.The creation of the color spot is because the melanin precipitates cause, and the melanin become, general and the human body endocrine function is to is closely related.

 

Because our Lao ammonia in the body is sour the sour  is at the Lao ammoniaOf function bottom, will oxidize much borner Ba, then oxidize many Bases, will come together born melanin finally.And the Lao ammonia sour activity is the influence that is subjected to the human body endocrine axis-pituitary gland to secrete the melanin cell to stimulate hormone(the melanin stimulation hormore, MSH), and estrogen, the prostate gland hormone control.Therefore be the condition of the melanin formation:The Lao ammonia is sour, the Lao ammonia sour , The oxygen and the melanin body increment, the Lao ammonia in the body the activity of the sour An will also become high, When the content increase, will become melanin.

 

 

How reduce melanin formation

Now that the melanin is a sour  because of the Lao ammoniaLive augmentative cause, so repress sour  of the Lao ammoniaOf activity, the clearance live oxygen or free radicals, reduce ultraviolet ray project light upon, arrestment oxidize to respond occurrence etc., is direct reduce resist the melanin formation of valid way.

 

Have no special effect method still currently for various prevention and cure of color spot, widespread recognize the formation of the in bar of melanin, ease or downplay dye calm and steady, or fair product adopted to contain a fair of the Department of Health laws, most ability valid control dye of proliferation;Take to have the vitamin C, vitamin E, the anti- free radicals enzyme of the melanin formation of repress or eat food with abundant vitamin C besides, as the fruit, vegetable...etc., or avoid sunlight projecting light upon, using to defending to insolate cosmetics or defend to insolate tools and implements excessively etc., is all way that resists to have the color spot skin.