4.
Antisymmetry in the system of canonical amino acids
4.1. Antisymmetric properties
of the side chains of the canonical set of amino acids
Pay attention, that among the amino acids side
chains we find pairs.
1.There are a pairs of amino acids with similar properties but different
chain lengths: - aspartic (Asp) and glutamic (Glu) acids (Table)
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2.Some pairs of amino acids differ in their properties, but have similar
size: - serine (Ser) and cysteine (Cys) (Table) - tryptophan and
tyrosine.
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Pairs (1) have a
quasi-mirror antisymmetry. |
Pairs (2) possess not mirror antisymmetry. |
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3. Some amino acids form a pair on the basis of opposites of their
properties: aspartic acid (Asp) has acidic properties, and arginine (Arg) -
alkaline (table), similarly, a pair of glutamic |
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4. It is possible to
oppose a number of amino acids on weight: - short amino acid
serine (Ser) can be contrasted with the massive amino acid - tryptophan (Trp)
(Table), - more heavier -
threonine (Thr) – to lighter than the tryptophan - histidine (His). |
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Pairs (3) are
antisymmetric in charge. |
Pairs (4) are
antisymmetric by weight. |
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All of these types of antisymmetry will be visually
presented as a result of construction of our system of amino acids.
4.2. Antisymmetry, revealed by
system of canonical amino acids
In the course of construction of system of amino
acids on the dodecahedron we explicitly
or implicitly used the principles of antisymmetry. Now, when the system is constructed, we will
consider the general features of antisymmetric groups of amino acids. For this purpose, for
each type of symmetry, we will use different color backgrounds in the circles,
in which the side chains of amino acids are situated.
4.2.1. Quasi-mirror antisymmetry
Antisymmetric amino
acids, which are located on both sides of the plane I, we call quasi-mirror
plane. They form pairs, which have similar physical characteristics but
different chain length or weight. They are connected by
the transformation, which we designate by the letter alpha (a). To the right of a plane I there were
shorter or lighter side chains (they are shown on light green background),
and at the left - longer or more heavy (dark-green background). To see this in more detail,
please see 4.2.1. |
Fig. 19. Coloring of amino acids connected by the quasi-mirror antisymmetry. |
4.2.2.
Not
mirror antisymmetry
The side chains of
amino acids having not mirror
antisymmetry, are located on the dodecahedron on opposite sides of the plane II:
behind the plane II (background in the circles is painted in pale pink), and
prior to that plane (dark pink background). For brevity we shall speak: behind a plane and prior a plane, the name referring to the plane II. They are connected among themselves by
transition which we have designated by the letter beta (b). In this case the side
chains in pairs usually have similar size but different physical properties.
In the section 4.2.2. pairs of side chains
of amino acids discussed in more detail. |
Fig. 20. An arrangement of the side chains in pairs of the amino acids connected by not mirror
antisymmetry. Behind a
plane II - circles of pale pink colour, before a plane II - dark pink
colour. |
This type of
antisymmety arises for two groups of side chains, which are located above and
below the plane III, separating the dodecahedron into two parts: upper and
lower. If the upper part of
the dodecahedron, in which the side chains of amino acids are represented in the circles of pink, rotate around an
axis in the plane III, the vertices of the upper part coincide with the vertices of the bottom part of the dodecahedron, in which the side
chains of amino acids placed in the light blue circles. The resulting pair of
side chains are connected among themselves by
transformation of rotation, which we denoted by the letter gamma (g). They have opposite properties and the different size. In section 4.2.3. these pairs are analyzed in more
detail. |
Fig. 21. Position on the dodecahedron of
side chains of amino acids connected by
rotary antisymmetry. |
4.2.4. Antisymmetry of complementarity
If we connect the opposite vertices of the dodecahedron by diameters, the side chains of amino acids
located at these vertices form a complementary pairs. This type of antisymmetry may be named
as antisymmetry of complementarity. The resulting pairs of side-chains
linked by three transformations: a, b, and g. They have as much as possible opposite size and properties, and if we
compare the pairs, starting from the right side and left side, then these
properties as would be compensated. More detailed analysis of the
antisymmetry of complementarity is done in Section 4.2.4. |
Fig. 22.
Position on the dodecahedron of side chains of amino acids connected by antisymmetry of complementarity. |
4.3. Transformations of amino acids at transition
through antisymmetry planes
Since we have three planes
of antisymmetry transition to antisymmetric amino acid through these planes can
be designated in the same way as in section 2.3.,
by any letter. Following designations have been entered:
- amino acid transition in
itself is designated by figure 1.
- transition through a
plane I - the letter a
(alpha),
- transition through a
plane II - the letter b (beta);
- rotation around an axis laying in a plane III -
the letter g (gamma).
Then it is possible to
describe all transformations of the amino acids located in a column 1, in each
group in the form of the following table.
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1 |
a |
b |
g |
ab |
ag |
bg |
abg |
Subgroup 1 |
Gly |
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Pro |
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Subgroup 2 |
Ala |
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Leu |
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Subgroup 3 |
Ser |
Thr |
Cys |
His |
Met |
Trp |
Phe |
Tyr |
Subgroup 4 |
Asp |
Glu |
Asn |
Arg |
Gln |
Lys |
Val |
Ile |
So, we have shown that a system of
canonical side chains of amino acids, constructed by us, allows to visualize
the four types of anti-symmetry, which
exist for them:
quasi-mirror, not mirror, rotary and antisymmetry of
complementarity.
From this fact we can make
the following conclusion:
possibility of imposing (superposition) of all four
types of antisymmetry for the given system of amino acids testifies that the
offered variant of spatial structure of amino acids on the dodecahedron is
unique. It
is impossible to carry out a permutation of amino acids without affecting any
type of antisymmetry
Do not believe me - try it yourself.
Address
for connection: amino-acids-20@yandex.ru