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核核核核 Nucleic Acid Chemistry

核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

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Page 1: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

核酸化学

Nucleic Acid Chemistry

Page 2: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

contents

1 introduction

2 compositiong

3 Structure

4 nucleic acid and nucleotide property

Page 3: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

ⅠIntroduction

1868, Fridrich Miescher first isolated nuclein from pyocyte( 脓细胞) .

1.discovery and development of nucleic acid

Page 4: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

1944 O.Avery confirmed DNA is hereditary substance.

Page 5: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

1953 J.Watson F.Crick discovered DNA double helix.

 Rosalind Franklin and Maurice Wilkins showed in the early 1950s that DNA produces a characteristic x-ray diffraction pattern

                            A Erwin Chargaff in the late 1940s. They found that the four nucleotide bases in DNA

Page 6: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

1968, Nirenberg found the genetic code .

Marshall W. Nirenberg

Page 7: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

2. classification, distributing and function of nucleic acids

DNA RNA

laying Nucleus90%,mitochondrium, autoplast, plasmid.

Nucleus, cytochyma

function Having genetic information and deciding genotye of body.

Jion in genetic expression.

Page 8: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Ⅱ composition of nucleic acid

DNA RNA

base Purine bases

嘌呤碱Adenine 腺嘌呤

(A)Adenine 腺嘌呤 (A)

Guanine 鸟嘌呤 (G)

Guanine 鸟嘌呤 (G)

Pyrimidine bases

嘧啶碱

Cytosine 胞嘧啶 (C)

Cytosine 胞嘧啶 (C)

Thymine 胸腺嘧啶(T)

Uracil 尿嘧啶 (U)

pentose D-2-deoxyribose D-2- 脱氧核糖

D-ribose

D- 核糖acid phosphoric acid

磷酸phosphoric acid

磷酸

Page 9: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Nucleic Acids

Nucleotide

phosphate Ribonucleoside(deoxyribonucleoside)

base Pentose

Purine (A 、 G)

Pyrimidine (C 、 T 、 U)

deoxyriboseribose

Page 10: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Nucleotide

Page 11: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

pentose

Page 12: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Base

Page 13: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

9

8

16

3

7

2

1

1

8

6

7

3

1

3

Page 14: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Ribonucleoside

cytidine 胞苷 CR guanine deoxyriboside 脱氧鸟苷 dGR

Page 15: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

The linkage of base with ribose(2-deoxyribose)

Page 16: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Deoxyribonucleotides

The product of deoxyribonucleoside linking of phosphoric acid at 5’ position.

Page 17: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

ribonucleotides

Page 18: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Important nucleotides

Page 19: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 20: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

minor bases

Page 21: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

ΨI

Page 22: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Ⅲ structure of nucleic acid

1 、 structure of DNA

(1) The primary structure The primary structure of a nucleic acid is its co

valent structure and nucleotide sequence.

Page 23: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

DNA was formed by linking of deoxynucleotides with phosphodiester bond at 3’ position of one deoxynucleotide and 5’ position of another deoxynucleotide.

The primary structure

Page 24: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 25: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(2) Secondary structure – Double-stranded helix

CharacteristicThe two strands are antiparallel. The chain, phosphoric acid and deoxyribose, locate lateral of the helix, but bases are in the helix. Pair strictly A to T, G to C. A turn contains 10 nucleotides, with height 3.4nm. Width 2.0nm. Form a major groove and a minor groove. Rotating right-handed. The maintaining force of the structure is hydrogen-bond.

Page 26: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Pairs bases

Page 27: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Watson and Crick 2.0 nm

小沟

大沟

The Nobel Prize in Physiology or Medicine 1962 (1953)

Page 28: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

A-DNA is favored when DNA is dehydrated. Major and minor grooves are similar in width.

B-DNA is the conformation normally found inside cells.

Z-DNA is favored in certain G/C-rich sequences. No grooves left handed helix

Versatility of DNA double helix

Page 29: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Versatility of DNA double helix

Page 30: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

two sets of forces, as described earlier:

1. hydrogen bonding between complementary base pairs

2. base-stacking interactions.

forces

Page 31: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(3) Tertiary structure of DNA----supercoil

Further coil of the DNA double helix.

(positive supercoil) (negative supercoil)

Page 32: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(1) Containing genetic information, as the template of gene duplication , DNA finally directs protein biosynthesis. As a result, keeping hereditary characters of body. (2) Gene refer to a segment of DNA chain which posseses a special biological function.

(4) Function of DNA

Page 33: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

2. spatial structure and function of RNA

Nuclus and cytochyma

mitochondrium

function

核蛋白体RNA

rRNA mt rRNA Component of ribosome

信使 RNA mRNA mt mRNA Template of protein synthesis

转运 RNA tRNA mt tRNA Transport amino acids

不均一核RNA

HnRNA Precursor of mature mRNA

小核 RNA SnRNA Jion in hnRNA splicing and transporting

小核仁 RNA

SnoRNA Processing and modifying of rRNA

RNAs in animal cell

Page 34: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(1) mRNA --messenger RNA

5’cap:m7GpppNm-

3’Poly A tail : An n=20—200

Single chain

half life time from munits to hours

Page 35: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 36: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

In prokaryotes a single mRNA molecule may code for one or several polypeptide chains. If it carries the code for only one polypeptide, the mRNA is monocistronic; if it codes for two or more different polypeptides, the mRNA is polycistronic. In eukaryotes, most mRNAs are monocistronic. mRNAs transcribed from DNA are always somewhat longer than needed simply to specify the code for the polypeptide sequence(s). The additional noncoding RNA includes sequences that regulate protein synthesis .

Page 37: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(2) tRNA

--transfer RNA

★ Stem-loop structure, cloverleaf pattern 三叶草形 .

★ 3 loop and 1 arm: DHU loop, anticoden loop, Tφloop, AA arm.

★ Anticoden and CCA-OH 3’end.

★ Contain rare bases 10%-20%.

Secondary structure

Page 38: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

tRNA tertiary structure:

a inverse L like.

Page 39: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

small subunit

large subunit

mRNAlocation

EF-G

tRNA

tRNA functions as a amino acid transfer in protein biosynthesis.

Page 40: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 41: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

(3) rRNA

--ribosomal RNA

Weight 80% of total RNA in a cell.

Flower like.

Component of ribosome.

procaryote : 5S,16S,23S;

eukaryote: 18S,5S,5.8S,28S

Page 42: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 43: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Ⅳ nucleic acid and nucleotide property

Page 44: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Nucleic acids get their maximum

absorption at 260nm.

DNA solution : A260 / A280=1.8;

RNA solution : A260 / A280= 2.0

OD260=1.0, equal to 50μg/ml DS DNA,

40μg/ml SS DNA or RNA.

1. Ultraviolet absorption

Page 45: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

• hyperchromic effect • The large increase in light absorption at 260 nm occurrin

g as a double-helical DNA is melted (unwound).  •   • hypochromic effect • The close interaction between stacked bases in a nucleic acid

has the effect of decreasing the absorption of UV light relative to a solution with the same concentration of free nucleotides. This is called the hypochromic effect.

Page 46: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

2. DNA denaturation

--the double chain change into single chain

Methods: heat, acid, base, urea, acetone

Result: OD260↑, viscosity↓, activity lose.

Page 47: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Tm

--melting temperature, 解开链温度,融解温度, refer to   the middle point of temperature range of DNA thermal denaturation .

The temperature of 50% double chain undoing.

Tm=69.3+0.41(G+C)%

Page 48: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property
Page 49: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Renaturation and hybridizationRenaturation: the single DNA chains recover their natural double helix structure.

Annealing 退火 : renaturation of thermal denatural DNA, by way of slow cooling.

Page 50: 核酸化学 Nucleic Acid Chemistry. contents 1 introduction 2 compositiong 3 Structure 4 nucleic acid and nucleotide property

Hybridization 杂交: phenomenon of single chain DNA or RNA bind the chain different origin in renaturation process.