I= CHARACTERIZATION OF CAMEL MILK B-CASEIN
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Title of Thesis
CHARACTERIZATION OF CAMEL MILK B-CASEIN

Author(s)
Ashiq Muhammad
Institute/University/Department Details
University f Karachi/ H.E.J. Research Institute of Chemistry
Session
1993
Subject
Chemistry
Number of Pages
85
Keywords (Extracted from title, table of contents and abstract of thesis)
camel milk, casein, proteins, peptides, amino acid, camelus dromedaries

Abstract
Present study was undertaken to characterize camel milk caseins. The major objective was to isolate, purify and elucidate the structure of caseins (known classes of proteins as well as unidentified proteins)

Primary structure of β-casein has been investigated along with partial characterization of novel N-terminally blocked casein

β-casein was purified by ion exchange chromatography and its structure was determined by analysis of intact protein and peptides generated by enzymatic cleavage I.e. Lys-C, Arg specific and Asp-N by manual (DABITC) as well as on gas phase sequence. Camel milk β-casein contains 217 amino acid residues with molecular mass of 28600 dalton (on the absis 64%, 63% 48%, 62% homology. Camel β-casein shows 40% conservation to afore mentioned β-casein. It shows an extension of 7 residues at its C-terminal when compared to bovine, ovine and buffalo β-casein. It has a number of short tandem repeats. Primary structure of β-casein shows several biologically active peptides i.e. β-casomorphin, angiotensin-1 converting enzyme inhibitor, immunostimulating peptides and a large number of opioid peptides

Partial characterization of a novel casein has been achieved from acid precipitated camel milk casein. It was purified by reversed phase HPLC. It has molecular mass of 25 kDa as determined of SDS-PAGE. Sequence studies revealed that it was N-terminally blocked. The amino acid analysis differs from known classes of casein i.e. as1, as2, β and k-casein. It’s distinct nature stdnds out due to the absence of praline and methionine, which has been found in caseins characterized till date

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents 0
94.35 KB
2 1 Introduction 1
149.31 KB
  1.1 General Introduction 1
  1.2 Classification Of Milk Proteins 3
  1.3 Non Classified Milk Proteins 3
  1.4 Caseins 5
  1.5 Biological Active Peptides 17
  1.6 Objective Of Present Studies 20
3 2 Experimental 21
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  2.1 Collection Of Milk Sampls 21
  2.2 Preparation Of Casein 21
  2.3 Purification Of Casein 21
  2.4 Electrophoresis 23
  2.5 Cleavage Of Intact Protein 26
  2.6 Amino Acid Analysis 27
  2.7 Amino Acid Sequencing Of Protein And Oeorides 27
4 3 Results 31
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  3.1 Separation Of Crude Casein By Ion Exchange 31
  3.2 Characterization On Electrophoresis 31
  3.3 Densitometric Scanning Of Acid Precipitated Camel Milk 31
  3.4 N-Terminal Sequence Analysis 31
  3.5 Enzymatic Fragmentation Of Peptides Purification 32
  3.6 Primary Structure Of Camel ( Camelus Dromedaries) Milk Β-Casein 42
  3.7 Purification Of 25 kDA Protein From Camel Milk Casein 42
  3.8 N-Terminal Sequence Analysis Of 25 kDA Protein 42
5 4 Discussion 46
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  4.1 Preliminary Characterization Of 25 kDA N-Terminal Blocked Protein From Camel Milk Casein 46
  4.2 Primary Structure 46
  4.3 Preliminary Characterization Of Β-Casein 46
  4.4 Primary Structure Of Β-Casein 47
  4.5 Canservation And Variation In The Structure Of Β-Casein From Camel Milk 48
  4.6 Comparison Of Camel Milk Β-Casein With Characterized Β-Casein Fragment 48
  4.7 Predicted Β- Casomorphic Region In Camel Milk Β-Casein 56
  4.8 Predicted Opioid Peptides Region In Camel Milk Β-Casein And Their Comparison With Opiods From Other Sources 57
  4.9 Predicted Phosphorylation Sites In Camel Milk Β-Casein 60
  4.10 Predicted Region Of Angiotensin-1 Converting Enzyme (Ace-1) Inhibitors 60
  4.11 Predicted Region Of Immunostimulating Casein Peptides 62
  4.12 Short Tandem Repeats And Their Possibility In Structural Stability 63
  4.13 Structure Function Relationship 66
  4.14 Conclusions 67
6 5 References 68
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