Changes

<p>일반적인 &alpha;-아미노산의 구조는 다음과 같다. COOH | H-C-'''R''' | NH₂ 여기서 &quot;R&quot;은 [[곁사슬]](side chain)을 나타내고, 곁사슬에 따라 무슨 아미노산인지가 결정된다. 아미노산은 곁사슬의 성질에 따라 산성, 염기성, 친수성(극성), 소수성(비극성)의 네 가지 종류로 구분될 수 있다. 그러나, 목적에 따라 더 많은 종류로 분류되기도 한다. 곁사슬 [[수소원자]]뿐인 글라이신([[glycine]])을 제외하고, 다른 아미노산은 모두 두가지 [[광학 이성질체|광학 활성]]을 갖아, D형과 L형으로 구분된다. [[단백질]](protein)을 구성하는 아미노산의 거의 대부분은 [[L-아미노산]] 형태로 존재한다. 청자고둥(cone snail)같은 일부 특이한 바다생물에서 D-아미노산이 발견되기도 했다. 단백질은 아미노산의 축합중합을 통해 만들어진다.:<br /> </p><p>1. 아미노산; 2, 쯔비터이온(zwitterion) 구조; 3, 펩티드 결합(peptide bond)을 이루는 두 개의 아미노산 유전암호(genetic code)로 다음 20개의 아미노산을 나타낸다.:<br />[[Image:Amino_acids_1Amino_acids_2.png]]곁사슬의 화학적 성질 </p><table cellspacing="0" cellpadding="2" border="1"> <tbody> <tr> <th colspan="2">약자</th> <th>이름</th> <th>곁사슬 성질</th> <th>질량</th> <th>[[Isoelectric point]]</th> <th>비고</th> </tr> <tr> <td>A</td> <td>Ala</td> <td>알라닌(Alanine)</td> <td>소수성</td> <td>89.09</td> <td>6.11</td> </tr> <tr> <td>C</td> <td>Cys</td> <td>시스테인(Cysteine)</td> <td>친수성</td> <td>121.16</td> <td>5.05</td> <td>Two cysteines can form a [[disulfide bond]].</td> </tr> <tr> <td>D</td> <td>Asp</td> <td nowrap="">아스파르트산(Aspartic acid)</td> <td>산성</td> <td>133.10</td> <td>2.85</td> </tr> <tr> <td>E</td> <td>Glu</td> <td nowrap="">글루탐산(Glutamic acid)</td> <td>산성</td> <td>147.13</td> <td>3.15</td> </tr> <tr> <td>F</td> <td>Phe</td> <td>페닐알라닌(Phenylalanine)</td> <td>소수성</td> <td>165.19</td> <td>5.49</td> </tr> <tr> <td>G</td> <td>Gly</td> <td>글리신(Glycine)</td> <td>친수성</td> <td>75.07</td> <td>6.06</td> <td>&alpha;-탄소에 두 개의 수소가 붙어 있기 때문에, 광학 이성질체를 갖지 않는다. </td> </tr> <tr> <td>H</td> <td>His</td> <td>히스티딘(Histidine)</td> <td>염기성</td> <td>155.16</td> <td>7.60</td> </tr> <tr> <td>I</td> <td>Ile</td> <td>이소루신(Isoleucine)</td> <td>소수성</td> <td>131.17</td> <td>6.05</td> </tr> <tr> <td>K</td> <td>Lys</td> <td>리신(Lysine)</td> <td>염기성</td> <td>146.19</td> <td>9.60</td> </tr> <tr> <td>L</td> <td>Leu</td> <td>루신(Leucine)</td> <td>소수성</td> <td>131.17</td> <td>6.01</td> </tr> <tr> <td>M</td> <td>Met</td> <td>메티오닌(Methionine)</td> <td>소수성</td> <td>149.21</td> <td>5.74</td> </tr> <tr> <td>N</td> <td>Asn</td> <td>아스파라긴(Asparagine)</td> <td>친수성</td> <td>132.12</td> <td>5.41</td> </tr> <tr> <td>P</td> <td>Pro</td> <td>프롤린(Proline)</td> <td>소수성</td> <td>115.13</td> <td>6.30</td> <td>Can disrupt protein folding structures like [[alpha helix|&alpha; helix]] or [[beta sheet|&beta; sheet]].</td> </tr> <tr> <td>Q</td> <td>Gln</td> <td>글루타민(Glutamine)</td> <td>친수성</td> <td>146.15</td> <td>5.65</td> </tr> <tr> <td>R</td> <td>Arg</td> <td>아르기닌(Arginine)</td> <td>염기성</td> <td>174.20</td> <td>10.76</td> </tr> <tr> <td>S</td> <td>Ser</td> <td>세린(Serine)</td> <td>친수성</td> <td>105.09</td> <td>5.68</td> </tr> <tr> <td>T</td> <td>Thr</td> <td>트레오닌(Threonine)</td> <td>친수성</td> <td>119.12</td> <td>5.60</td> </tr> <tr> <td>V</td> <td>Val</td> <td>발린(Valine)</td> <td>소수성</td> <td>117.15</td> <td>6.00</td> </tr> <tr> <td>W</td> <td>Trp</td> <td>트립토판(Tryptophan)</td> <td>소수성</td> <td>204.23</td> <td>5.89</td> </tr> <tr> <td>Y</td> <td>Tyr</td> <td>티로신(Tyrosine)</td> <td>친수성</td> <td>181.19</td> <td>5.64</td> </tr> </tbody></table><table cellspacing="0" cellpadding="2" bordercolor="black" border="1"> <tbody> <tr> <th align="middle">아미노산</th> <th align="middle">소수성</th> <th align="middle">positive</th> <th align="middle">negative</th> <th align="middle">polar</th> <th align="middle">charged</th> <th align="middle">small</th> <th align="middle">tiny</th> <th align="middle">aromatic</th> <th align="middle">aliphatic</th> <th>[[Induced-dipole attraction|van der Waals]] volume</th> </tr> <tr> <td><strong>Ala</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td>67</td> </tr> <tr> <td><strong>Cys</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>86</td> </tr> <tr> <td><strong>Asp</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>91</td> </tr> <tr> <td><strong>Glu</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>109</td> </tr> <tr> <td><strong>Phe</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td>135</td> </tr> <tr> <td><strong>Gly</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td>48</td> </tr> <tr> <td><strong>His</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td>118</td> </tr> <tr> <td><strong>Lys</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>135</td> </tr> <tr> <td><strong>Ile</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td>124</td> </tr> <tr> <td><strong>Leu</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td>124</td> </tr> <tr> <td><strong>Met</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>124</td> </tr> <tr> <td><strong>Asn</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>96</td> </tr> <tr> <td><strong>Pro</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>90</td> </tr> <tr> <td><strong>Gln</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>114</td> </tr> <tr> <td><strong>Arg</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>148</td> </tr> <tr> <td><strong>Ser</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td>73</td> </tr> <tr> <td><strong>Thr</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td>93</td> </tr> <tr> <td><strong>Val</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td>105</td> </tr> <tr> <td><strong>Trp</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td>163</td> </tr> <tr> <td><strong>Tyr</strong></td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle">-</td> <td align="middle"><strong>X</strong></td> <td align="middle">-</td> <td>141</td> </tr> </tbody></table><p><br /></p>