.
Chao Chen
Abstract: Based on mathematics, biochemistry, molecular biology and other natural sciences, and under the guidance of the thought of “Book of Changes” (YiJing), the four bases in RNA: adenine, guanine, cytosine and urine pyrimidine are considered to be the four elements of yin and yang, namely the taiyang, shaoyang, shaoyin, and taiyin. Sixty-four codons are considered to be sixty-four hexagrams. According to the physical and chemical properties of the bases, combined with the sequence of binary natural numbers, each codon is given a digital code to form a digital RNA codon table. The feature of this table is that according to the change of the second base U, C, G, A of the codon, an ordered non-polar hydrophobic region, non-polar polar region, polar basic region, and polar base are formed. According to the change of the first base U, C, G, A of the codon, four periodic cycles are formed. The digitized codon periodic table reveals the intrinsic relationship between codons and amino acid physicochemical properties, deepens people’s knowledge and understanding of gene expression, and also provides a theoretical basis for innovative gene sequencing methods.
Key words: Genetic Code, Amino acid, Digitizing, Periodic table, YiJing
Life is how proteins exist. Proteins are made up of various amino acids in a specific order. Information about the ordered assembly of amino acids to form proteins is stored in DNA or RNA molecules. Each DNA or RNA molecule is composed of bases, pentose sugars and phosphates. The pentose sugar in DNA is deoxyribose, while the pentose sugar in RNA is ribose; this is the difference between the two structures. DNA and RNA molecules can store and transmit genetic information. The genetic information of life is contained in the sequence of four bases. The so-called gene sequencing is to determine the order of four bases in DNA or RNA molecules. In RNA molecules, the four bases are adenine (A), guanine (G), cytosine (C), and uracil (U), while in DNA molecules, uracil (U) is replaced by thymine (T). Wherein, every three bases constitute a set of codons (Codon), corresponding to a standard amino acid or a termination signal. According to the arrangement formula, these 4 bases are repeatedly arranged at 3 positions in the polynucleotide chain, and finally 64 kinds of codons will be formed, that is, 4^3=64. In the last century, through the efforts of many scientists, the corresponding relationship between the 64 codons and amino acids was discovered one after another, and finally the RNA codon table was compiled by British scientist Clark［1］. According to the base sequences of U, C, A, and G, the table shows the corresponding relationship between the 64 codons and 20 amino acids through artificial arrangement, and summarizes many scientific research achievements in this field at that time. Unfortunately, however, Clarks codon table did not reveal the inner connection and basic principle behind the codon bases and physicochemical properties of amino acids.
his research is based on natural sciences such as mathematics, biochemistry, and molecular biology, as well as the guidance of the “Book of Changes”, to hypothesize that the purine and pyrimidine base pairs of C and G, A and U can be considered yin and yang. The four bases: adenine, guanine, cytosine and uracil map on to the four phenomena, namely the taiyang, shaoyang, shaoyin and taiyin. The sixty-four codons can be explained to match the sixty-four hexagrams, reconstructing the RNA codon table.
To digitize the sixty-four codons, the first step is that the four bases are encoded according to their basic physicochemical properties. The functional group of the base is an important part that determines the chemical properties of its organic matter, its yin-yang properties are determined by the electronegativity of the associated atomic groups. The greater the electronegativity, the more likely the group is negative; the lower the electronegativity, the more likely the group is positive. The electronegativity of oxygen is 3.44, which is greater than 2.55 of carbon, so the carbonyl is negatively charged; the electronegativity of hydrogen is 2.2, which is significantly smaller than 3.04 of nitrogen, so the amino group is positive. Uracil has two carbonyl groups (>C=O), while cytosine has one carbonyl and one amino group (NH2). The carbonyl is negatively charged and belongs to Yin (indicated by 0 in binary mathematics), and the amino group is positively charged and belongs to Yang (expressed by 1). The number 00 is therefore used to represent the two carbonyl groups of uracil, and the number 01 is used to represent one carbonyl group and one amino group of cytosine.
Uracil has two negative carbonyl groups
number 00
cytosine has one negative carbonyl and one
positive amino group, number 01
In the second step, according to the principle［2］of uracil and adenine pairing, and cytosine and guanine pairing, the code of uracil is 00, so the code of adenine can only be 11, so that opposites attract and yin and yang pair up. The coding of cytosine is 01,so the coding of guanine can only be 10, in a way that opposites attract and yin and yang pair with each other.
In the third step, according to the RNA codon table, every three bases constitute a codon, corresponding to an amino acid. Therefore, triplet codons can be expressed digitally. For example, the codon UUU can be expressed with the number 000000, which corresponds to phenylalanine. The codon UUG, represented by the number 000010, corresponds to leucine. Then, according to the binary natural number sequence, the digital amino acid periodic table of genetic code can be compiled. It should be pointed out that this study is entirely based on the knowledge of mathematics, chemistry and molecular biology, without artificial assumptions. Through the natural progression of the Miguazi coding sequence, the corresponding physical and chemical properties of amino acids also appear in non-polar, polar, basic, and acidic orderly changes, and finally form a framework of four regions and four cycles, as shown in the attached table: ［Digital Gene Code – Periodic Table of Amino Acids］.
In the digitized gene code-amino acid periodic table, each codon-amino acid column contains the following basic content: 1. Code from binary natural sequence; 2. Triple codon; 3. Amino acid English single-letter code［3］; 4 .Natural sequence from decimal system; 5. English three-letter code of amino acid; 6. Chinese name of amino acid or termination signal.
1. The digitizing the periodic table of amino acids in the genetic code is divided into 4 regions according to the difference in the second base of the codon: non-polar hydrophobic region, non-polar & polar region, polar basic region, and polar basic acid region［4］, each region contains 4 codons, and the four regions contain 16 codons, forming a cycle. According to the difference of the first base of the codon, it is divided into four cycles of U, C, G, and A, with each cycle containing 16 codons; the four cycles, thus, contain a total of 64 codons. It is stated as follows:
1). Non-polar hydrophobic region: the second base of the triplet codon is uracil (U). Uracil has two negative carbonyl groups, which are yin within yin, and the decoded amino acids are all non-polar hydrophobic amino acids, including phenylalanine, leucine, valine, isoleucine, and methionine . From the perspective of nutrition, these five are essential amino acids for the human body; from the perspective of physical and chemical properties, they are all conservative amino acids, of which leucine, valine, and isoleucine are branched-chain amino acids; phenylalanine is an Aromatic amino acid; methionine (methionine) is the initiation signal.
2). Non-polar polar region:the second base of the triplet codon is cytosine (C). Cytosine has a negative carbonyl group and a positive amino group, thus, containing both yin and yang. It can decode 4 amino acids, of which two are positive polar amino acids: 〖JP+1〗serine and threonine, and two are negative non-polar amino acids: proline and alanine. Although proline and alanine are classified as non-polar amino acids, their isoelectric potentials［5］are 6.3 and 6.02, respectively, which are higher than other non-polar amino acids (usually below 6). In some cases, both are also classified as polar molecules. Therefore, both are more reactive amino acids compared to the rest of the non-polar amino acids.
3). Polar basic region: the second base of the triplet codon is guanine (G). Guanine is a double-ring structure, chemically active, and belongs to yang; it has a positive amino group and a negative carbonyl group, which is more yang and less yin. Most of the amino acids decoded by it are positive polar amino acids and positively charged basic amino acids. Only one negative non-polar amino acid and termination signal. The 4 polar amino acids are: glycine, cysteine, serine, and arginine. Arginine is the most basic standard amino acid, which belongs to the yang of yang. Therefore, they are active amino acids in terms of physicochemical properties. Although tryptophan is a nonpolar amino acid, it is sometimes slightly polar due to its unique side chain［6］.
The solitary yin of tryptophan does not grow, and the solitary yang of arginine does not grow, leading to the termination signal that the extremes of things must be reversed. (The termination signal UGA can decode tryptophan in human mitochondria. The codons AGG and AGA of arginine are termination signals in human mitochondria.) In this periodic table, tryptophan, arginine and termination signals are close neighbors, which shows the internal relationship between them.
4). Polar basic acid region:the second base of the triplet codon is adenine (A). Adenine is also a double-ring structure, which belongs to yang, has a positive amino group, making it yang within yang, and the amino acids decoded by it are all yang amino acids, including 3 kinds of polar amino acids: asparagine, glutamine, tyrosine; 2 basic amino acids (yang within yang): histidine and lysine; 2 acidic amino acids (yin within yang): aspartic acid and glutamic acid. In a certain pH range, asparagine and aspartic acid, glutamine and glutamic acid can be converted into each other［7］. This area also includes two termination signals UAG and UAA. (The termination signals UAG and UAA can be decoded as glutamine in Paramecium.) In this periodic table, asparagine and aspartic acid, glutamine and glutamic acid, glutamine and termination signal are in a neighbor relationship, showing the intrinsic relationship between them.
From the above explanation, it can be seen that the second base in the codon has an important influence on the physicochemical properties of the corresponding amino acid. The second base of the codon determines the physical and chemical properties of the corresponding amino acids and forms a four-region and four-cycle framework, which is an important feature of the new code periodic table.
2. The digital genetic code amino acid periodic table, according to the difference of the first base of the codon, is divided into four sequences: U, C, G, and A; all three aromatic amino acids and termination signals are classified into the U sequence, all acidic amino acids are assigned to the G sequence, and all basic amino acids are assigned to the C and A sequences. Although the second base is important for decoding amino acids, it also requires the participation of the first base. For another example, the four codons whose bases 1 and 2 are C all correspond to proline, and the four codons whose bases 1 and 2 are G all correspond to glycine, and they are not affected by the third base; However, codons whose first and second bases are U or A require the participation of the third base to correctly decode amino acids. The codons of the G and C sequences are relatively stable, probably because the base pairs of C and G have three hydrogen bond supports; while the codons of the U and A sequences are relatively sensitive, because the base pairs of A and U have only two hydrogen bond supports, variant codons are susceptible to microenvironmental influences［8］. From the perspective of the entire periodic table, the codons in the polar basic regions and polar basic acidic regions of U and A sequences are the most sensitive and are easily affected by the microenvironment, and altered code words (altered code words) appear. Existing experiments can prove the conjecture of this periodic table: UGA is a termination signal, but it can decode tryptophan in human mitochondria. AGG and AGA are codons for arginine, but they are termination signals in human mitochondria. UAA and UAG are termination signals, but can decode glutamine in Paramecium. These mutated codons are all in the U and A sequences, and when the microenvironment changes, they mutate into messages with similar neighboring codons. In this periodic table, tryptophan, arginine and the termination signal are neighbors, and glutamine and the termination symbol are also neighbors. According to the codon cycle law revealed in this table, it should not be surprising to find that AAG and AAA become variant codons under certain conditions.
3. According to molecular biology, the codon of messenger ribonucleic acid (mRNA) can determine the corresponding amino acid and benefit from the help of transfer ribonucleic acid (tRNA). tRNA can recognize codons on mRNA and also amino acids. Because the second base of the codon has a strong role in determining the amino acid. If the second base on the messenger ribonucleic acid is uracil (U), which is negative, and the second base on the anticodon of the transfer ribonucleic acid is adenine (A), which is positive, and then the positive transfer ribose nucleic acid is combined with negative amino acid. In this way, opposites attract and the law of yin and yang pairing runs through the entire process of gene expression and protein synthesis. From the perspective of modern science, the positive and negative electromagnetic force (such as ionic bond force, etc.), van der Waals force (such as dispersion force, induction force, etc.), and hydrogen bond force between molecules or groups should be the physical and chemical basis for the matching of yin and yang and the attraction of opposites［9］.
In summary, the digital genetic code table not only includes all the information of the traditional codon table, but also has the following notable features:
1). According to the physical and chemical properties of the base, use the binary natural number sequence to give each codon a digital code. This code is the mathematical expression of the physical and chemical properties of the base, providing a new theoretical basis for digital gene sequencing.
2). According to the conversion of the second base U, C, G, A of the codon, orderly non-polar regions, four-region alternation of non-polar & polar regions, polar basic regions and polar basic acid regions are formed. The second base in the codon has a decisive influence on the physical and chemical properties of the corresponding amino acid, and its degree of influence is arranged in the order of C, U, G, A. When the second base is U or C (especially C), the third base has little effect on codon decoding amino acid; when the second base is G or A (especially A), the third base has an important influence on the decoding ability of the codon.
3). According to the conversion of the first base U, C, G, A of the codon, four cycles of U, C, G, A are formed. Codons with the first base of C and G have a relatively stable ability to decode amino acids; while codons with the first base of U and A are more sensitive and easily affected by the environment, forming mutated codons. Most of these mutated codons are in U and A sequences. When the microenvironment changes, they generate mutated information and have properties similar to adjacent codons.
4). Opposites attract and the law of yin and yang pairing runs through the entire process of gene expression and protein synthesis. The positive and negative electromagnetic force, van der Waals force, and hydrogen bond force between molecules or groups should be the physical and chemical basis for the matching of yin and yang, as well as the attraction of opposites［9］.
These features breathe life into traditional codon tables. The digitization and periodicity of the gene codon table provides a powerful tool for the interpretation and application of molecular biology, while also providing a guiding map for continuing to explore the unknown areas of molecular biology.
Authors:
M.D.，Acupuncturist in Fort Lauderdale, Florida.
References
(1)(8) Klug, W.& Cumming, M. Genetics: A Molecular Perspective ［M］，Prentice Hall, New Jersey, USA , 2003:107-108
(2）宋今丹主编，医学细胞生物学［M］，北京：人民卫生出版社，1997:35-36
(3) Bhagavana, N.V. Medical Biochemistry［M］, Jone and Bartlett Publishers, Boston, USA, 1992:20
(4)(9) Chao Chen, Periodic Circle of Codons & Amino Acids, US Copyright Office, USA, 2008:2-3
(5)Odian,G.& Blei,I. Genaral,Organic and Biological Chemistry［M],Mc Graw-hill, USA, 1994:385
(6) (7)Eastwood, M. Principles of Human Nutrition［M］, Blackwell Publishing, Edinburgh, UK , 2003:156-159
数字化基因密码—氨基酸周期表
陳超
摘要:本研究在數學，生物化學，分子生物學等自然科學的基礎上，在《易經》思想的指導下，把RNA中的四種鹼基：腺嘌呤，鳥嘌呤，胞嘧啶和尿嘧啶視作陰陽四象，即太陽，少陽，少陰，太陰。把六十四種密碼子視作六十四卦。根據鹼基的理化性質，配合二進制的自然數列，賦予每個密碼子一個數字編碼，構成了數字化的RNA密碼子表。該表的特點就是根據密碼子第二鹼基U，C，G，A的變化，形成了有序的非極性疏水區，非極性極性區，極性鹼性區，以及極性鹼性酸性區; 根據密碼子第一鹼基U，C，G，A的變化，形成四個週期性的循環。數字化的密碼子週期表 揭示了密碼子和氨基酸理化性質的內在關聯，深化了人們對基因表達的認識和理解，也為創新基因測序方法提供了理論基礎。
關鍵詞:基因密碼子，氨基酸，數字化，週期表，易經
生命是蛋白質的存在方式。蛋白質則由多種氨基酸按照特定順序構成。氨基酸有序組裝形成蛋白質的信息就貯存在DNA或 RNA的分子裡。每個DNA或 RNA的分子均由鹼基，戊糖，和磷酸組成。 DNA的戊糖為脫氧核糖，RNA中則為核糖，這是兩者的一個不同之處。 DNA和RNA分子能夠貯存和傳遞遺傳信息，生命的遺傳信息就包含在四種鹼基的序列中，所謂基因測序，就是測定四種鹼基在DNA或RNA分子中的排列順序。在RNA分子中，四種鹼基分別是腺嘌呤(A)，鳥嘌呤(G)，胞嘧啶(C)和尿嘧啶(U)，DNA分子則由胸腺嘧啶(T)代替尿嘧啶(U)。其中，每三個鹼基形成一組密碼子(Codon)，對應一種標準氨基酸或者停止信號。按照排列公式，四種鹼基，在多核苷酸鏈的三個位置上重複排列，最終會形成64種密碼子，即4^3=64。上世紀，在眾多科學家的努力下，64個密碼子和氨基酸的對應關係已被陸續發現，最後由英國科學家克拉克編成RNA密碼子表［1］。該表通過人為的排列，按照U，C，A，G的鹼基順序，展現了64個密碼子和20種氨基酸的對應關係，較好地總結了當時該領域的眾多科研成果。遺憾的是，克拉克的密碼子表，並沒有揭示出密碼子的鹼基和氨基酸理化性質的內在聯繫和深層原理。
本研究在數學，生物化學，分子生物學等自然科學的基礎上，在《易經》思想的指導下，把C和G，A和U的嘌呤嘧啶鹼基對，視作陰陽兩儀。把四種鹼基：腺嘌呤，鳥嘌呤，胞嘧啶和尿嘧啶視作四象，即太陽，少陽，少陰，太陰。把六十四種密碼子視作六十四卦，重構了RNA密碼子表。
為了把六十四種密碼子數字化，第一步，根據四種鹼基的基本理化特徵進行編碼。鹼基的官能團是決定其有機物化學性質的重要構成，其陰陽性質由相關原子團的電負性決定，電負性越大，基團易顯示陰性；電負性小，基團易顯示陽性。氧的電負性是3.44，大於碳的2.55，因此，羰基現陰性；氫的電負性是2.2，明顯小於氮3.04，因此，氨基現陽性。尿嘧啶帶有二個羰基(>C=O)，而胞嘧啶帶著一個羰基，一個氨基(NH2)。羰基帶負電，屬陰(二進制數學用0表示)，氨基帶正電，屬陽，(用1表示)。因此，用數碼00代表尿嘧啶的二個羰基，用數碼01代表胞嘧啶的一個羰基和一個氨基。
尿嘧啶有2個陰性羰基，編碼00：
胞嘧啶有一個陰性羰基，一個陽性氨基，編碼01：
第二步，根據尿嘧啶和腺嘌呤配對，胞嘧啶和鳥嘌呤配對的原則［2］，尿嘧啶的編碼為00，那麼腺嘌呤的編碼只能是11，這樣才能異性相吸，陰陽配對。胞嘧啶的編碼為01，那麼鳥嘌呤的編碼只能是10，這樣才能異性相吸，陰陽配對。
第三步，根據RNA密碼子表，每三個鹼基構成一個密碼子，對應一種氨基酸。因此，三聯密碼子就可以用數碼來表達。例如，密碼子UUU，可以用數碼000000來表達，對應苯丙氨酸。密碼子UUG，用數碼000010來表達，對應亮氨酸。然後根據二進制的自然數列，就能夠編寫出數字化的基因密碼氨基酸週期表。需要指出的，本研究完全基於數學，化學和分子生物學知識，並無人為的假設。通過密卦子編碼序列的自然遞進，其相應的氨基酸理化性質也隨之出現了非極性，極性，鹼性，酸性的有序變化，最後形成四區四周期的構架，見附表：【數字化基因密碼-氨基酸週期表】。
在數字化基因密碼-氨基酸週期表中，每個密碼子-氨基酸欄包含了下列基本內容： 1.來自二進制自然數列的編碼; 2.三聯密碼子; 3.氨基酸英文單字母代號［3］; 4.來自十進制的自然序列; 5.氨基酸英文三字母代號; 6.氨基酸中文名稱或終止信號。
一，數字化基因密碼氨基酸週期表，根據密碼子第二位鹼基不同，分成4區：非極性疏水區，非極性&極性區，極性鹼性區，和極性鹼性酸性區［4］,每區含4個密碼子，四區含16個密碼子，構成一個週期。根據密碼子第一位鹼基不同，又分成U，C，G，A四個週期，每週期含16個密碼子，四個週期共含64個密碼子。茲述如下：
1. 非極性疏水區: 三聯密碼子第二鹼基均為尿嘧啶(U)。尿嘧啶有二個陰性羰基，是陰中有陰， 其解碼的氨基酸都是非極性疏水性的氨基酸，包括苯丙氨酸，亮氨酸，纈氨酸，異亮氨酸，甲硫氨酸。從營養學來看，這五種都是人體必需氨基酸；從理化性質來看，它們都是保守氨基酸，其中亮氨酸，纈氨酸，異亮氨酸是支鏈氨基酸；苯丙氨酸為芳香族氨基酸；甲硫氨酸(蛋氨酸)則是啟動信號。
2. 非極性極性區:三聯密碼子第二鹼基均為胞嘧啶(C)。胞嘧啶有一個陰性羰基，一個陽性氨基， 有陰有陽。它能解碼4種氨基酸，2種是屬陽的極性氨基酸：絲氨酸和蘇氨酸；2種是屬陰的非極性氨基酸：脯氨酸和丙氨酸。雖然脯氨酸和丙氨酸歸類於非極性氨基酸，但其等電位［5］分別是6.3和6.02，高於其它非極性氨基酸（通常 為 6以下）。在某些情況下，兩者也被歸類於 極性分子。因此， 與其餘非極性 氨基酸相比，兩者是較活躍的氨基酸。
3.極性鹼性區：三聯密碼子第二鹼基均為鳥嘌呤(G)。鳥嘌呤是雙環結構，化學性質活躍，屬陽；有一個陽性氨基，和一個陰性羰基，屬多陽少陰，其所解碼的氨基酸多數是屬陽的極性氨基酸，帶正電荷的鹼性氨基酸；僅有一個屬陰的非極性氨基酸以及終止信號。4種極性氨基酸是：甘氨酸，半胱氨酸，絲氨酸，和精氨酸。精氨酸是鹼性最強的標準氨基酸，屬陽中之陽。因此，從理化性質來看，它們是活躍的氨基酸。色氨酸雖為非極性氨基酸，由於其獨特的側鏈，有時也有輕度的極性［6］。
色氨酸的孤陰不生，精氨酸的獨陽不長，導致物極必反的終止信號。(終止信號UGA，在人的線粒體裡能夠解碼色氨酸。精氨酸的密碼子AGG 和AGA，在人的線粒體裡是終止信號。) 在本週期表裡，色氨酸，精氨酸和終止信號是近鄰關係，可見它們之間的內在關聯 。
4.極性鹼性酸性區：三聯密碼子第二鹼基均為腺嘌呤(A)。腺嘌呤也是雙環結構，屬陽，有一個陽性氨基，屬陽中有陽，其所解碼的氨基酸都是屬陽的氨基酸，包括3種極性氨基酸：天冬酰胺，谷氨酰胺，酪氨酸；2種鹼性氨基酸(陽中之陽)：組氨酸，賴氨酸；2種酸性氨基酸(陽中之陰)：天冬氨酸和谷氨酸。在一定的pH值範圍，天冬酰胺和天冬氨酸，谷氨酰胺和谷氨酸能夠相互轉化［7］。該區尚包括兩種終止信號UAG和UAA 。 (終止信號 UAG 和UAA，在草履蟲裡能解碼為 谷氨 酰胺 )在本週期表裡，天冬酰胺和天冬氨酸，谷氨酰胺 和谷氨酸，谷氨酰胺和終止信號 均為近鄰 關係 ，可見它們之間的內在關聯。
由上可見，密碼子中第二鹼基對相應氨基酸的理化性質有重要影響。密碼子第二鹼基決定相應氨基酸的理化性質，並形成四區四周期構架，是新密碼週期表的一個重要特色。
二，數字化基因密碼 氨基酸週期表，根據密碼子第一位鹼基的不同，左右分成U，C，G，A四個序列;所有三種芳香族氨基酸和終止信號，均歸類於U序列；所有酸性氨基酸歸類於G序列；所有鹼性氨基酸歸類於C和A序列。雖然第二鹼基對解碼氨基酸有重要作用，但也需要第一鹼基的參與。又如第1，2鹼基為C的四個密碼子，均對應脯氨酸，第1，2鹼基為G的四個密碼子均對應甘氨酸，它們並不受第3鹼基的影響; 而第1，2鹼基為U或A的密碼子則需要第3鹼基 參與才能正確解碼氨基酸。G和C序列 的密碼子比較穩定，可能由於C和G鹼基對有三個氫鍵支持；而U和A序列的密碼子比較敏感，因為A和U鹼基對僅有二個氫鍵支撐，容易受到微環境的影響而出現變異密碼子［8］。從整個週期表來看，U和A序列的極性鹼性區和極性鹼性酸性區，其密碼子最敏感，極易受到微環境的影響，而出現變異的密碼子 (altered code words)。現有的實驗可以證明本週 期表的推測 ：UGA是終止 信號，但 在人的線粒體裡能夠解碼色氨酸。 AGG和AGA 是精氨酸的密碼子，但在人的 線粒體裡 卻是終止信號。UAA和UAG是終止信號，但在草履蟲裡能夠解碼谷氨酰胺。這些變異密碼子都在U和A序列，當微環境發生變化時，它們變異成具有類似鄰近密碼子的信息。在本週期表中，色氨酸，精氨酸和終止信號是近鄰關係，谷氨酰胺和終止符號也是近鄰關係。根據本表所揭示的密碼子週期規律，若發現AAG和AAA在特定條件下成為變異密碼子，也不應感到驚訝。
三，根據分子生物學，信使核糖核酸(mRNA)的密碼子之所以能決定相應的氨基酸，得益於轉移核糖核酸(tRNA)的幫助。 tRNA既能識別mRNA上的密碼子，又能識別氨基酸。因為密碼子第2鹼基有決定氨基酸的強大作用。如果信使核糖核酸上的第二鹼基是尿嘧啶(U)，屬陰性，那麼在轉移核糖核酸反密碼子上的第二鹼基則是腺嘌呤(A)，屬陽，然後陽性的轉移核糖核酸又去結合屬於陰性的氨基酸。如此，異性相吸，陰陽配對的規律貫穿基因表達，蛋白質合成的整個過程。從現代科學的角度看，分子或基團間的正負電磁力（如離子鍵力等），範得華力（如色散力，誘導力等）以及氫鍵力等, 應是陰陽相配,異性相吸的理化基礎［9］。
綜上所述，數字化基因密碼表不僅囊括了傳統密碼子表所有的信息，而且具有下列顯著的特色：
1.根據鹼基的理化性質，用二進制自然數列，賦予每個密碼子一個數字編碼。這個編碼是鹼基理化性質的數理表達，為數字化的基因測序提供新的理論基礎。
2.根據密碼子第二鹼基U，C，G，A的變換，形成了有序的非極性區，非極性&極性區，極性鹼性區和極性鹼性酸性區的四區交替。密碼子中第二鹼基對相應氨基酸的理化性質有決定性影響，其影響度按C，U，G，A次序排列。當第二鹼基為U或C時(尤其是C)，第三鹼基對密碼子解碼氨基酸影響很小；當第二鹼基為G或A 時(尤其是A)，第三鹼基對密碼子的解碼能力有重要影響。
3.根據密碼子第一鹼基U，C，G，A的變換，又形成U，C，G，A四個週期。第一鹼基為C，G的密碼子，具有相對穩定的解碼氨基酸能力；而第一鹼基為U，A的密碼子，則比較敏感，容易受環境的影響，形成變異密碼子。這些變異密碼子大多在U和A序列，當微環境發生變化時，它們產生變異的信息，具有類似鄰近密碼子的性質。
4.異性相吸，陰陽配對的規律貫穿基因表達，蛋白質合成的整個過程。分子或基團間的正負電磁力, 範得華力, 以及氫鍵力等, 應是陰陽相配,異性相吸的理化基礎［9］。
這些特色為傳統密碼子表注入了生命活力。基因密碼子表的數碼化和周期性為分子生物學的闡釋和應用提供了一種有力的工具，為繼續探索分子生物學的未知領域提供了導向圖。
作者簡介：
陳超 醫學博士，佛羅裏達州勞德代爾堡執業的針灸師。
