Nucleoproteins (NP)


Huge discoveries was made in this field of (knowledge) biochemistry in the last 30-40 years. The discoveries in this field have greit significance and led to the appeareince and development of molecular biology, molecular genetic, biotechnology, genetic engineering and genetic surgery.

NP are acid proteins (due to huge content of phosphoric acid), they are dissolved in water and alkali solutions, but they are not dissolved in acid solution.

The molecular mass of nucleoproteins are from some millions to some milliards daltons. They consist of a s.p. and prosthetic group called nucleic acids.

The NP-s play huge role in the living organisms: they transfer the genetic information from the parients to the posterity during reproduction; from one cell to another cell (during division of cells); from the nucleic acids to the proteins (during the biosynthesis of proteins). So they have next ability: to store, express and transmit genetic information.

Protein part of NP consist of large number molecules of histones (in animals and men) or protamines (in the fish and sea animal), acid albumines and glombulines.

Histones (H) have an important role in the defence DNA, in the keeping of the structure of chromosomes, in the regulation expression of genes.

Nonhistone proteins are enzymes and regulate expression of genes too.

 

 

The purine bases: adenine, guanine; pyrimidene bases: cytosine, uracile, thymine.

Besides these bases minorbases (seldom meeting bases) are found out in structure NA.

The purine bases are derivatives of condenced heterocycles pyrimidine and imidazole.

The pyrimidine bases are derivates of heterocycle pyrimidine.

 

NP

 

SP Prosthetic group – NA-s (polynucleoti-

des) = n mononucleotides (or nucleoti-

des, or nucleosidphosphoric acids)

n> 1000

(histones, protamines, albumins, globulins)

Mononucleotides

Nucleoside Phosphoric a.

Pentose Nitrogenous bases

 

 

Ribose Deoxyribose Purines Pyrimidines (cytosine, uracil, thymin)

(adenine, guanine)

 

Adenine (6-aminopurine) Thymine (5-methyluracil)

 

 

Guanine (2-amino, 6-oxypurine) Uracil (2,6-dihydroxypyrimidine)

 

 

Cytosine (2-hydroxy, 6-aminopyrimidine)

 

The mentioned above bases are jointed with pentose and form nucleosides. When nitrogenous bases are jointed with ribose they are named ribo nucleosides and are included in structure RNA (f.e. adenosine, guanosine, cytidile, uridile). When they are jointed with deoxyribose they are named deoxynucleosides are included in structure DNA only a symbol “d” to put before their name – deoxyadenosine – d-adenosine, deoxythymidine – d-thymidine.

When nucleosides or d-nucleosides are jointed with p.a. by ether bonds they form nucleotides or nucleosidephosphates (see tabl.). The quantity of p.a. may be 1, 2, 3.

The second and third molecules of p.a. are jointed to nucleotides by macroergic bonds ( bonds with very high energy – high energy bonds ~ (symbol) – 33 nj/mole).

 



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