Download - Nonstandard Aminoacids1
-
8/12/2019 Nonstandard Aminoacids1
1/31
Non-standard Aminioacids
-
8/12/2019 Nonstandard Aminoacids1
2/31
Non-standard Amino acids:
Are they abnormal amino acids?
Are they unusual amino acids?
1 .Protein forming amino acids - 20 amino acids
Posttranscriptional modification
2. Non-standard Amino acids
(A) Non-protein amino acids
Function -Structural
FunctionAs a metabolite
As a regulator of metabolic activities
(B) D amino acid
-
8/12/2019 Nonstandard Aminoacids1
3/31
Protein phosphorylation is widely exploited in DNA damage
repair, signal transduction, cell growth and cell cycle regulation;
The cascades of downstream signals can be triggered by grabbing a
certain phosphoprotein .
Elucidating the characteristics of phosphopeptide recognition is
fundamental to study cellular functions .
-
8/12/2019 Nonstandard Aminoacids1
4/31
The phosphoproteins are usually classified into two families,
phosphotyrosine(pTyr)-containing and
phosphoserine (pSer)/phosphothreonine (pThr)-containingsequences .
They are phosphorylatedand dephosphorylatedby different
categories of kinases(e.g., pThr/pSer kinase and pThr kinase) and
phosphatases .
Recent studies discovered a few modular domains that particularly
recognizepThr/pSer- or pThr-containing sequences, such as the
breast-cancer-associated protein BRCA1 C-terminal (BRCT)repeats, WW domain and forkhead-associated (FHA) domain .
-
8/12/2019 Nonstandard Aminoacids1
5/31
Phosphorylation and sulfation
Some of the tyrosine residues can be taggedwith a phosphate
group by protein kinases.It is referred to as phosphotyrosine.
Tyrosine phosphorylation is considered to be 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).
-
8/12/2019 Nonstandard Aminoacids1
6/31
Phosphoserineis an esterof
serineand phosphoric acid
catalyzed by various types ofkinases.
Phosphoserine is a component
of many proteins as the result of
posttranslational modificaations.
Phosphorylation of proteins on
serine and threonine residues
has traditionally been viewed as
a means to allosterically regulatecatalytic activity.
PhosphoserineModifications, like
phosphorylation: A common
mechanism for controlling the
behavior of a protein,;
For eg. activating or inactivating
an enzyme.
http://en.wikipedia.org/wiki/Esterhttp://en.wikipedia.org/wiki/Serinehttp://en.wikipedia.org/wiki/Phosphoric_acidhttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Phosphorylationhttp://en.wikipedia.org/wiki/Phosphorylationhttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Phosphoric_acidhttp://en.wikipedia.org/wiki/Serinehttp://en.wikipedia.org/wiki/Ester -
8/12/2019 Nonstandard Aminoacids1
7/31
Phosphothreonine
The threonine residue is susceptible to
numerous post-traslational modifications.
The hydroxy side-chain can undergo O-
linked glycosilation.
In addition, threonine residues undergo
phosphorylationthrough the action of a
threonine kinase.
In its phosphorylated form, it can bereferred to as phosphothreonine.
-
8/12/2019 Nonstandard Aminoacids1
8/31
-
8/12/2019 Nonstandard Aminoacids1
9/31
4-hydroxyproline: Found in plant cell wall
proteins; Synthesized in plant cells in response to
stress.
Hydroxyproline and Hydroxylysine are found in
collagen, a fibrous protein of connective tissues.Found in capillaries, bone and cartilage.
Proline and lysine are formed in the procollagen
and It is hydroxylated in the presence of ascorbic
acid. These hydroxylation help in the cross linkingof the collagen molecules and thereby stabilizing
structure of collagen.
Among these uncommon amino acids are 4-hydroxyproline, a derivative of
proline, and 5-hydroxylysine, derived from lysine.
-
8/12/2019 Nonstandard Aminoacids1
10/31
Another important uncommon amino
acid is -carboxyglutamate, found in
(1) bloodclotting protein prothrombin
and in(2) certain proteins that bind Ca2 as
part of their biological function.
6-N Methyllysine
is a constituent of myosin, a contractile protein of muscle.
-
8/12/2019 Nonstandard Aminoacids1
11/31
Elastinis a proteinin connective tissue
that is elasticand allows many tissues in
the body to resume their shape after
stretching or contracting. Elastin helps
skin to return to its original position whenit is poked or pinched. Elastin is also an
important load-bearing tissue in the
bodies of vertebrates.
In humans, elastin is encoded by the ELN
gene.This desmosineis responsible for the
rubber like properties of elastin.
Desmosine is a complex molecule; It isa derivative of four Lys
residues, and is found in the fibrous protein elastin.
http://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Elasticity_(physics)http://en.wikipedia.org/wiki/Genehttp://en.wikipedia.org/wiki/Genehttp://en.wikipedia.org/wiki/Elasticity_(physics)http://en.wikipedia.org/wiki/Connective_tissuehttp://en.wikipedia.org/wiki/Protein -
8/12/2019 Nonstandard Aminoacids1
12/31
Selenocysteine is a special case.
This rare amino acid residue is introduced
during protein synthesis.
Actually derived from serine,
selenocysteine is a constituent of just a
few known proteins.
Selenocysteine has a structure similar tothat of cysteine, but with an atom of
seleniumtaking the place of the usual
sulfur, forming a selenolgroup which is
deprotonated at physiological pH.
Proteins that contain one or more
selenocysteine residues are called
selenoproteins.
Solenocysteine (21-Sec -U)
Pyrrolysine (22Pyl -O)
Present in several Enzymes
(for example glutathione
peroxidases,
tetraiodothyronine 5'
deiodinases, thioredoxin
reductases, formate
dehydrogenases, glycinereductases, selenophosphate
synthetase 1, methionine-R-
sulfoxide reductase B1
(SEPX1), and some
hydrogenases)
http://en.wikipedia.org/wiki/Cysteinehttp://en.wikipedia.org/wiki/Seleniumhttp://en.wikipedia.org/wiki/Sulfurhttp://en.wikipedia.org/wiki/Glutathione_peroxidasehttp://en.wikipedia.org/wiki/Glutathione_peroxidasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Thioredoxin_reductasehttp://en.wikipedia.org/wiki/Thioredoxin_reductasehttp://en.wikipedia.org/wiki/Formate_dehydrogenasehttp://en.wikipedia.org/wiki/Formate_dehydrogenasehttp://en.wikipedia.org/wiki/Glycine_reductasehttp://en.wikipedia.org/wiki/Glycine_reductasehttp://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/SEPX1http://en.wikipedia.org/wiki/Hydrogenasehttp://en.wikipedia.org/wiki/Hydrogenasehttp://en.wikipedia.org/wiki/SEPX1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Selenophosphate_synthetase_1http://en.wikipedia.org/wiki/Glycine_reductasehttp://en.wikipedia.org/wiki/Glycine_reductasehttp://en.wikipedia.org/wiki/Glycine_reductasehttp://en.wikipedia.org/wiki/Formate_dehydrogenasehttp://en.wikipedia.org/wiki/Formate_dehydrogenasehttp://en.wikipedia.org/wiki/Formate_dehydrogenasehttp://en.wikipedia.org/wiki/Thioredoxin_reductasehttp://en.wikipedia.org/wiki/Thioredoxin_reductasehttp://en.wikipedia.org/wiki/Thioredoxin_reductasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Tetraiodothyronine_5_deiodinasehttp://en.wikipedia.org/wiki/Glutathione_peroxidasehttp://en.wikipedia.org/wiki/Glutathione_peroxidasehttp://en.wikipedia.org/wiki/Sulfurhttp://en.wikipedia.org/wiki/Seleniumhttp://en.wikipedia.org/wiki/Cysteine -
8/12/2019 Nonstandard Aminoacids1
13/31
N-Methylarginineis an inhibitorof nitric oxide synthase.
Chemically, it is a methylderivative of the amino acidarginine.It is used as a biochemical tool in the study of physiological
role of nitric oxide.
Nitric oxide transient in its function.
http://en.wikipedia.org/wiki/Enzyme_inhibitorhttp://en.wikipedia.org/wiki/Nitric_oxide_synthasehttp://en.wikipedia.org/wiki/Methylhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Argininehttp://en.wikipedia.org/wiki/Argininehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Methylhttp://en.wikipedia.org/wiki/Nitric_oxide_synthasehttp://en.wikipedia.org/wiki/Nitric_oxide_synthasehttp://en.wikipedia.org/wiki/Enzyme_inhibitor -
8/12/2019 Nonstandard Aminoacids1
14/31
Nitric oxide, also known as nitrogen monoxide, is a moleculewith
chemical formulaNO. It is a free radical.
In mammals including humans, NO is an important cellular signaling
moleculeinvolved in many physiological and pathological processes.
It is a powerful vasodilatorwith a short half-life of a few seconds in the
blood. (Dissection)
Long-known pharmaceuticals like nitroglycerineand amyl nitritewere
discovered, more than a century after their first use in medicine, to be
active through the mechanism of being precursors to nitric oxide.
Low levels of nitric oxide production are important in protecting organs
such as the liver from ischemic damage.
http://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Free_radicalhttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Nitroglycerinehttp://en.wikipedia.org/wiki/Amyl_nitritehttp://en.wikipedia.org/wiki/Ischemic_damagehttp://en.wikipedia.org/wiki/Ischemic_damagehttp://en.wikipedia.org/wiki/Amyl_nitritehttp://en.wikipedia.org/wiki/Nitroglycerinehttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Free_radicalhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Molecule -
8/12/2019 Nonstandard Aminoacids1
15/31
Acetyllysine(or acetylated lysine) is an acetyl-derivative of the
amino acidlysine. There are multiple forms of acetyllysine .
In proteins, the acetylationof lysine residues is an important
mechanism of epigenetics.
It functions by regulating the binding of histonesto DNAinnucleosomesand thereby controlling the expression of genes
on that DNA.
Non-histone proteins are acetylated as well.
Histone acetyltransferases(HATs) catalyze the addition of acetylgroups from acetyl-CoAonto certain lysine residues of histones
and non-histone proteins.
Histone deacetylases(HDACs) catalyze the removal of acetyl
groups from acetylated lysines.
http://en.wikipedia.org/wiki/Acetylhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Lysinehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Acetylationhttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Nucleosomehttp://en.wikipedia.org/wiki/Histone_acetyltransferaseshttp://en.wikipedia.org/wiki/Acetyl-CoAhttp://en.wikipedia.org/wiki/Histone_deacetylaseshttp://en.wikipedia.org/wiki/Histone_deacetylaseshttp://en.wikipedia.org/wiki/Histone_deacetylaseshttp://en.wikipedia.org/wiki/Histone_deacetylaseshttp://en.wikipedia.org/wiki/Acetyl-CoAhttp://en.wikipedia.org/wiki/Acetyl-CoAhttp://en.wikipedia.org/wiki/Acetyl-CoAhttp://en.wikipedia.org/wiki/Histone_acetyltransferaseshttp://en.wikipedia.org/wiki/Histone_acetyltransferaseshttp://en.wikipedia.org/wiki/Histone_acetyltransferaseshttp://en.wikipedia.org/wiki/Nucleosomehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/Acetylationhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Lysinehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Acetyl -
8/12/2019 Nonstandard Aminoacids1
16/31
-
8/12/2019 Nonstandard Aminoacids1
17/31
Non-protein aminoacids:
Some 300 additional amino acids have been found in cells.
They have a variety of functions but are not constituents of
proteins.
Ornithine and citrulline deserve special note because they
are key intermediates (metabolites) in the biosynthesis of
arginine and in the urea cycle .
-
8/12/2019 Nonstandard Aminoacids1
18/31
Citrulline is made from ornithineand carbamoyl phosphatein one ofthe central reactions in the urea cycle.
Function
Although citrulline is not coded for by DNA directly, several proteins areknown to contain citrulline as a result of a posttranslational modification.
These citrulline residues are generated by a family of enzymes called
peptidylarginine deiminases (PADs);
which convert arginine into citrulline in a process called citrullination ordeimination.
Proteins that normally contain citrulline residues include myelin basic
protein(MBP), filaggrin,and several histoneproteins,;
whereas other proteins, such as fibrinand vimentinare susceptible to
citrullination during cell death and tissue inflammation.
http://en.wikipedia.org/wiki/Ornithinehttp://en.wikipedia.org/wiki/Carbamoyl_phosphatehttp://en.wikipedia.org/wiki/Myelin_basic_proteinhttp://en.wikipedia.org/wiki/Myelin_basic_proteinhttp://en.wikipedia.org/wiki/Filaggrinhttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/Fibrinhttp://en.wikipedia.org/wiki/Vimentinhttp://en.wikipedia.org/wiki/Inflammationhttp://en.wikipedia.org/wiki/Inflammationhttp://en.wikipedia.org/wiki/Vimentinhttp://en.wikipedia.org/wiki/Fibrinhttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/Filaggrinhttp://en.wikipedia.org/wiki/Myelin_basic_proteinhttp://en.wikipedia.org/wiki/Myelin_basic_proteinhttp://en.wikipedia.org/wiki/Carbamoyl_phosphatehttp://en.wikipedia.org/wiki/Carbamoyl_phosphatehttp://en.wikipedia.org/wiki/Carbamoyl_phosphatehttp://en.wikipedia.org/wiki/Ornithine -
8/12/2019 Nonstandard Aminoacids1
19/31
Patients with rheumatoid arthritis often have detectable
antibodies against proteins containing citrulline.
Although the origin of this immune response is not known,
detection of antibodies reactive with citrulline (anti-
citrullinated protein antibodies) containing proteins or
peptides is now becoming an important help in the diagnosis
of rheumatoid arthritis.
In recent studies, citrulline has been found to relax blood
vessels.
Circulating citrulline concentration is, in humans, a biomarker
of intestinal functionality
http://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Rheumatoid_arthritishttp://en.wikipedia.org/wiki/Rheumatoid_arthritishttp://en.wikipedia.org/wiki/Rheumatoid_arthritishttp://en.wikipedia.org/wiki/Rheumatoid_arthritishttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibodyhttp://en.wikipedia.org/wiki/Anti-citrullinated_protein_antibody -
8/12/2019 Nonstandard Aminoacids1
20/31
Citrulline in the form of citrulline malateis sold as aperformance-enhancing athletic dietary supplement, which was
shown to reduce muscle fatigue in a preliminary clinical trial.
The rind of watermelon(Citrullus lanatus) is a good natural
source of citrulline.
http://en.wikipedia.org/wiki/Malic_acidhttp://en.wikipedia.org/wiki/Dietary_supplementhttp://en.wikipedia.org/wiki/Watermelonhttp://en.wikipedia.org/wiki/Watermelonhttp://en.wikipedia.org/wiki/Dietary_supplementhttp://en.wikipedia.org/wiki/Malic_acid -
8/12/2019 Nonstandard Aminoacids1
21/31
-
8/12/2019 Nonstandard Aminoacids1
22/31
L-Ornithine is one of the products of the action of the enzymearginaseon L-arginine, creating urea.
Ornithine is a central part of the urea cycle,
Ornithine is recycled and, in a manner, is a catalyst.
Ornithine is not an amino acid coded for by DNA.
However, in mammalian non-hepatic tissues, the main use of the
urea cycle is in arginine biosynthesis,;
so, as an intermediate in metabolic processes, ornithine is quite
important.
http://en.wikipedia.org/wiki/Arginasehttp://en.wikipedia.org/wiki/Argininehttp://en.wikipedia.org/wiki/Ureahttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Ureahttp://en.wikipedia.org/wiki/Argininehttp://en.wikipedia.org/wiki/Arginase -
8/12/2019 Nonstandard Aminoacids1
23/31
Ornithine,via the action of ornithine decarboxylase(E.C.4.1.1.17), is the starting point for the synthesis of polyaminessuch
as putrescine.
In bacteria, such as E. coli, ornithine can be synthesized from L-
glutamate.
Ornithine is also the starting point for cocainebiosynthesis, when
decarboxylased, then modified greatly by Cytochrome P450.
http://en.wikipedia.org/wiki/Ornithine_decarboxylasehttp://en.wikipedia.org/wiki/Polyaminehttp://en.wikipedia.org/wiki/Putrescinehttp://en.wikipedia.org/wiki/Escherichia_colihttp://en.wikipedia.org/wiki/Glutamic_acidhttp://en.wikipedia.org/wiki/Glutamic_acidhttp://en.wikipedia.org/wiki/Cocainehttp://en.wikipedia.org/wiki/Cytochrome_P450http://en.wikipedia.org/wiki/Cytochrome_P450http://en.wikipedia.org/wiki/Cytochrome_P450http://en.wikipedia.org/wiki/Cytochrome_P450http://en.wikipedia.org/wiki/Cocainehttp://en.wikipedia.org/wiki/Glutamic_acidhttp://en.wikipedia.org/wiki/Glutamic_acidhttp://en.wikipedia.org/wiki/Glutamic_acidhttp://en.wikipedia.org/wiki/Escherichia_colihttp://en.wikipedia.org/wiki/Putrescinehttp://en.wikipedia.org/wiki/Polyaminehttp://en.wikipedia.org/wiki/Ornithine_decarboxylasehttp://en.wikipedia.org/wiki/Ornithine_decarboxylasehttp://en.wikipedia.org/wiki/Ornithine_decarboxylase -
8/12/2019 Nonstandard Aminoacids1
24/31
Potential medical uses
Exercise fatigue
L-Ornithine supplementation attenuated fatigue in subjects in a placebo controlled study
using a cycle ergometer. The results suggested that L-ornithine has an antifatigue effect in
increasing the efficiency of energy consumption and promoting the excretion of
ammonia.
Stress
L-Ornithine reduced stress in mice and made them more sociable toward other mice as
well as the scientists conducting the experiment.
Cirrhosis
L-ornithine-L-aspartate (LOLA), a stable salt of ornithine and aspartic acid, has been used
in the treatment of cirrhosis.
Weightlifting supplement
Amino acidsupplements, including L-ornithine, are frequently used by body-builders and
weightlifters to increase levels of HGH. In a Finnish study, these supplements, in low
doses, were not found to increase levels of growth hormone.
However, the study did notadminister the amino-acids while the subjects were fasting, an important requirement in
testing for the effect of amino acids on HGH stimulation.
http://en.wikipedia.org/wiki/Hepatic_encephalopathyhttp://en.wikipedia.org/wiki/Cirrhosishttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/HGHhttp://en.wikipedia.org/wiki/HGHhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Cirrhosishttp://en.wikipedia.org/wiki/Hepatic_encephalopathy -
8/12/2019 Nonstandard Aminoacids1
25/31
-
8/12/2019 Nonstandard Aminoacids1
26/31
D-Aminoacids:
Post-translational modifications:
Modification involves conversion of amino acids in
peptide linkage the L- fprm to D-configurations.
Isolated from amphibians, snails and invertebrates.
-
8/12/2019 Nonstandard Aminoacids1
27/31
Peptides with D amino acids:
Bacterial peptides contain D- amino acids;
Eg. Tyrocidines and Gramicidin-S
These are by multi enzyme complex synthesis without the
participation of m-RNA.
Peptide bond with D-amino acids resist to proteases.
-
8/12/2019 Nonstandard Aminoacids1
28/31
D-amino acid containing peptides from Frog:
Dermorphin: Heptapeptide:
Tyr-D-Ala- Phe-Gly-Tyr-Pro-Ser amide
-Lys-
-Asn-
Deltrophin:
Tyr-D-Met-Phe-His-Leu-Met-Asp- amide
D-Ala Asp
D-Ala Glu
D-Alanine in
Dermorphin was
discovered when it was
found that the synthetic
peptide with the same
sequence of L-amino
acid was biologically
inactive.
-
8/12/2019 Nonstandard Aminoacids1
29/31
Frog: Bombicines: A group of antibacterial peptides;
D-allo-isok=leucines
Snail:Achatin I : Gly-D-Phe-Ala- Asp.
This regulates the muscle contraction.
Unusual aminoacids in peptide bonds:
Carnosinecontains -Alanine
Glutathionecontains gamma carboxy bond.
-
8/12/2019 Nonstandard Aminoacids1
30/31
Non-standard amino acids that are found in proteins are formed by
post-translational modification, which is modification after translation during protein
synthesis. These modifications are often essential for the function or regulation of a
protein; for example, the carboxylationof glutamateallows for better binding of
calcium cations,[38]and the hydroxylationof prolineis critical for maintaining
connective tissues.[39]
Another example is the formation of hypusinein thetranslation initiation factorEIF5A, through modification of a lysine residue.[40]Such
modifications can also determine the localization of the protein, e.g., the addition of long
hydrophobic groups can cause a protein to bind to a phospholipid membrane.[41]
http://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/Post-translational_modificationhttp://en.wikipedia.org/wiki/Carboxylationhttp://en.wikipedia.org/wiki/Glutamatehttp://en.wikipedia.org/wiki/Calcium_in_biologyhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Hydroxylationhttp://en.wikipedia.org/wiki/Prolinehttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Hypusinehttp://en.wikipedia.org/wiki/Eukaryotic_initiation_factorhttp://en.wikipedia.org/wiki/EIF5Ahttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/File:Beta_alanine_comparison.pnghttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/EIF5Ahttp://en.wikipedia.org/wiki/Eukaryotic_initiation_factorhttp://en.wikipedia.org/wiki/Hypusinehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Collagenhttp://en.wikipedia.org/wiki/Prolinehttp://en.wikipedia.org/wiki/Hydroxylationhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Calcium_in_biologyhttp://en.wikipedia.org/wiki/Calcium_in_biologyhttp://en.wikipedia.org/wiki/Glutamatehttp://en.wikipedia.org/wiki/Carboxylationhttp://en.wikipedia.org/wiki/Post-translational_modificationhttp://en.wikipedia.org/wiki/Post-translational_modificationhttp://en.wikipedia.org/wiki/Post-translational_modification -
8/12/2019 Nonstandard Aminoacids1
31/31
Some nonstandard amino acids are not found in proteins. Examples include
lanthionine, 2-aminoisobutyric acid, dehydroalanine, and the neurotransmitter
gamma-aminobutyric acid. Nonstandard amino acids often occur as intermediates
in the metabolic pathwaysfor standard amino acids for example, ornithineand
citrullineoccur in the urea cycle, part of amino acid catabolism(see below).[42]A
rare exception to the dominance of -amino acids in biology is the -amino acid
beta alanine(3-aminopropanoic acid), which is used in plants and microorganisms
in the synthesis of pantothenic acid(vitamin B5), a component of coenzyme A
http://en.wikipedia.org/wiki/Lanthioninehttp://en.wikipedia.org/wiki/2-aminoisobutyric_acidhttp://en.wikipedia.org/wiki/Dehydroalaninehttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Ornithinehttp://en.wikipedia.org/wiki/Citrullinehttp://en.wikipedia.org/wiki/Urea_cyclehttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Beta_alaninehttp://en.wikipedia.org/wiki/Pantothenic_acidhttp://en.wikipedia.org/wiki/Coenzyme_Ahttp://en.wikipedia.org/wiki/Coenzyme_Ahttp://en.wikipedia.org/wiki/Pantothenic_acidhttp://en.wikipedia.org/wiki/Pantothenic_acidhttp://en.wikipedia.org/wiki/Pantothenic_acidhttp://en.wikipedia.org/wiki/Beta_alaninehttp://en.wikipedia.org/wiki/Beta_alaninehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Urea_cyclehttp://en.wikipedia.org/wiki/Citrullinehttp://en.wikipedia.org/wiki/Ornithinehttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Gamma-aminobutyric_acidhttp://en.wikipedia.org/wiki/Dehydroalaninehttp://en.wikipedia.org/wiki/2-aminoisobutyric_acidhttp://en.wikipedia.org/wiki/2-aminoisobutyric_acidhttp://en.wikipedia.org/wiki/2-aminoisobutyric_acidhttp://en.wikipedia.org/wiki/Lanthionine