Acid hydrolysis ofproteins 6N HCI 110C 24 or 48 or 72hr Trp Ser thr Asn gin H HH H H H N- N--c-coo H3N-C-CO0+'H:3N-C-Co0 R O R R HPLC or ion-exchange 6M HCI Free amino chromatography Amino acid acids com position Polypeptide
Acid hydrolysis of proteins • 6N HCl 110℃ 24 or 48 or 72hr • Trp • Ser Thr • Asn Gln
Amino acid analysis Table 5.2 Amino Acid Composition of Some Selected Proteins Values expressed are percent representation of each amino ac Proteins* Amino acid RNase ADh Mb Histone H3 Collagen Ala 697598 13.3 Ars 37321.7 13.3 Asn 762.120 0.7 A sp 414.550 3.0 3.0
Amino acid analysis Table 5.2 Amino Acid Composition of Some Selected Proteins Values expressed are percent representation of each amino acid. Proteins* Amino Acid RNase ADH Mb Histone H3 Collagen Ala 6.9 7.5 9.8 13.3 11.7 Arg 3.7 3.2 1.7 13.3 4.9 Asn 7.6 2.1 2.0 0.7 1.0 Asp 4.1 4.5 5.0 3.0 3.0
The sequence of amino Acids in a protein is a unique characteristic of every protein is encoded by the nucleotide sequence of DNA is thus a form of genetic information is read from the amino terminus to the carboxyl terminus
The Sequence of Amino Acids in a Protein • is a unique characteristic of every protein • is encoded by the nucleotide sequence of DNA • is thus a form of genetic information • is read from the amino terminus to the carboxyl terminus
The sequence of ribonuclease A 124 HOOC(Val) 120 Phe l19 Pro GIn 110 Serl lle The ys)84 H 2N
The sequence of ribonuclease A
5.2 Architecture of proteins Shape-globular or fibrous The levels of protein structure Primary -sequence Secondary - local structures-H-bonds Tertiary -overall 3-dimensional shape Quaternary -subunit organization
5.2 Architecture of Proteins • Shape - globular or fibrous • The levels of protein structure - Primary - sequence - Secondary - local structures - H-bonds - Tertiary - overall 3-dimensional shape - Quaternary - subunit organization