scholarly journals Chemical and physical characteristics of a phosphoprotein from human parotid saliva

1975 ◽  
Vol 145 (3) ◽  
pp. 557-567 ◽  
Author(s):  
A Bennick
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Magnetic Resonance ◽  
Protein A ◽  
Chemical Analyses ◽  
Terminal Sequence ◽  
Parotid Saliva ◽  
Ester Linkage ◽  
Human Parotid Saliva ◽  
Phenylalanine Residue

The isolation of a highly purified phosphoprotein, previously named protein A, from human parotid saliva is described. This protein has an unusually high amount of glycine, proline and dicarboxylic amino acids. Together these amino acids account for 80% of all residues. The protein contains 1.9mol of P/mol of protein, probably as phosphate in an ester linkage to serine, and about 0.5% carbohydrate, but no hexosamine. The N-terminal is blocked and the following C-terminal sequence is proposed: -Aal-Asp-Ser-Gln-Gly-Arg-Arg. The sioelectric point is 4.43. The molecular weight of the protein determined by ultracentrifugation is 9900 and from chemical analyses 11000. Circular-dichrosim and nuclea-magnetic-resonance spectra indicate the absence of polyproline and triple-helical-collagen-like structure for the protein. There is little restriction on the orientation of the single phenylalanine residue in the protein., but there is also an indication of conformational restraint in the protein.

The C-terminal sequence of amino acid residues of κ-casein isolated from buffalo's milk

1967 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
W. Manson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Peptide Chain ◽  
Amino Acid Residues ◽  
Terminal Sequence ◽  
Carboxypeptidase A ◽  
Phosphorous Content ◽  
Single Peptide

SummaryWhen κ-casein from buffalo's milk was treated with carboxypeptidase A (EC 3. 4. 2. 1),4 amino acids, valine, threonine, serine and alanine were released from the protein in a manner consistent with the view that they originate in the C-terminal sequence of a single peptide chain. The amounts produced suggest a minimum molecular weight for buffalo κ-casein of approximately 17000, in agreement with the value calculated from the phosphorous content on the basis of the presence of 2 phosphorus atoms/molecule. A comparison is made with the C-terminal sequence reported for bovine κ-casein.

Characterization of Low-molecular-weight Peptides in Human Parotid Saliva

1995 ◽  
Vol 74 (1) ◽  
pp. 345-350 ◽  
Author(s):  
H.E.R. Perinpanayagam ◽  
B.C. VanWuyckhuyse ◽  
Z.S. Ji ◽  
L.A. Tabak
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Parotid Saliva ◽  
Human Parotid Saliva

Peptide Conformations. I. Nuclear Magnetic Resonance Study of the Carbamate Reaction of Amino Acids and Peptides

1971 ◽  
Vol 49 (5) ◽  
pp. 767-776 ◽  
Author(s):  
R. U. Lemieux ◽  
M. A. Barton
Keyword(s):  
Amino Acids ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Amide Bond ◽  
Resonance Spectroscopy ◽  
Peptide Conformations ◽  
End Distance ◽  
Phenylalanine Residue ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectroscopy has been applied to the study of carbamate formation in solutions of amino acids and peptides in a carbonate-bicarbonate system. The possible conformations of these carbamates are discussed in terms of the n.m.r. data obtained. The n.m.r. parameters are reported for the diastereomers L-alanyl-L or D-phenylalanine and L-phenylalanyl-L or D-alanine and for the dipeptide glycyl-L-phenylalanine and their carbamates. The results are interpreted in terms of preferred rotamers about the Cα—Cβ bond of the phenylalanine residue and a β-type conformation of the peptide chain, wherein the two α-protons lie in the plane of the amide bond. All observations are in agreement with a shorter end to end distance in L,D- compared with L,L-dipeptides.

scholarly journals Human U4/U6 snRNP Recycling Factor p110: Mutational Analysis Reveals the Function of the Tetratricopeptide Repeat Domain in Recycling

2004 ◽  
Vol 24 (17) ◽  
pp. 7392-7401 ◽  
Author(s):  
Jan Medenbach ◽  
Silke Schreiner ◽  
Sunbin Liu ◽  
Reinhard Lührmann ◽  
Albrecht Bindereif
Keyword(s):  
Amino Acids ◽  
Protein Interactions ◽  
Rna Binding ◽  
Mutational Analysis ◽  
Protein A ◽  
Tetratricopeptide Repeat ◽  
Terminal Sequence ◽  
Recognition Motifs ◽  
Tpr Domain

ABSTRACT After each spliceosome cycle, the U4 and U6 snRNAs are released separately and are recycled to the functional U4/U6 snRNP, requiring in the mammalian system the U6-specific RNA binding protein p110 (SART3). Its domain structure is made up of an extensive N-terminal domain with at least seven tetratricopeptide repeat (TPR) motifs, followed by two RNA recognition motifs (RRMs) and a highly conserved C-terminal sequence of 10 amino acids. Here we demonstrate under in vitro recycling conditions that U6-p110 is an essential splicing factor. Recycling activity requires both the RRMs and the TPR domain but not the highly conserved C-terminal sequence. For U6-specific RNA binding, the two RRMs with some flanking regions are sufficient. Yeast two-hybrid assays reveal that p110 interacts through its TPR domain with the U4/U6-specific 90K protein, indicating a specific role of the TPR domain in spliceosome recycling. On the 90K protein, a short internal region (amino acids 416 to 550) suffices for the interaction with p110. Together, these data suggest a model whereby p110 brings together U4 and U6 snRNAs through both RNA-protein and protein-protein interactions.

scholarly journals The identification of a peptide in human parotid saliva particularly active in enhancing the glycolytic activity of the salivary micro-organisms

1975 ◽  
Vol 149 (2) ◽  
pp. 489-492 ◽  
Author(s):  
I B Holbrook ◽  
P C Molan
Keyword(s):  
Molecular Weight ◽  
Peptide Analysis ◽  
Parotid Saliva ◽  
Basic Peptide ◽  
Glycolytic Activity ◽  
Micro Organisms ◽  
Human Parotid Saliva

A factor in saliva responsible for markedly activating the glycolytic activity of micro-organisms was isolated from parotid secretions and identified as a small basic peptide. Analysis of the peptide showed a high proportion of histidine, lysine and arginine. Its minimum molecular weight was calculated to be between 2500 and 3000.

Purification and Some Properties of Fucosyltransferase in Human Parotid Saliva

1987 ◽  
Vol 66 (1) ◽  
pp. 72-77 ◽  
Author(s):  
H. Tamagawa ◽  
E. Inoshita ◽  
T. Takeshita ◽  
M. Takagaki ◽  
S. Shizukuishi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Enzyme Activities ◽  
Chromatographic Analysis ◽  
Metal Ion ◽  
Divalent Metal ◽  
Parotid Saliva ◽  
Divalent Metal Ion ◽  
Human Parotid Saliva

Fucosyltransferase was purified from human parotid saliva by affinity chromatography on GDP-hexanolamine Sepharose, followed by chromatofocusing on PBE 94 exchanger gel. The purified enzyme had the N-acetylglucosaminide α1→4, the N-acetylglucosaminide α1→3, and the glucoside α1→3 fucosyltransferase activities. The molecular weight of the purified enzyme was estimated to be approximately 20,000. These enzyme activities showed identical pH and divalent metal ion dependencies and identical rates of inactivation upon being heated. The paper chromatographic analysis of the fucosylated products by the purified enzyme and the susceptibility of these products to linkage-specific fucosidase digestion indicated that the transferase formed the Fuc α1→4GlcNAc, Fuc α1→3GlcNAc, and Fuc α1→3Glc linkages.

scholarly journals The binding of calcium to a salivary phosphoprotein, protein A, common to human parotid and submandibular secretions

1976 ◽  
Vol 155 (1) ◽  
pp. 163-169 ◽  
Author(s):  
A Bennick
Keyword(s):  
Calcium Binding ◽  
Protein C ◽  
Equilibrium Dialysis ◽  
Protein A ◽  
Side Chain ◽  
Carboxyl Groups ◽  
Parotid Saliva ◽  
Submandibular Saliva ◽  
Hydrolysis Of ◽  
Human Parotid Saliva

The binding of Ca2+ to a previously described phosphoprotein from human parotid saliva, protein A [Bennick (1975) Biochem J. 145, 557-567] was studied by means of equilibrium dialysis. In 5 mM-Tris/HC1 buffer, pH7.5, protein A bound 664nmol of Ca/mg of protein. Km was determined to be 181 muM and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ apparently occurs to side-chain carboxyl groups in the protein, but protein phosphate is of minor if any importance in calcium binding. Hydrolysis of protein A by trypsin and collagenase or heating of the protein at 60 degrees or 100 degrees C did not affect Ca2+ binding. The Ca2+ binding decreases with increased concentration of the dialysis buffer and on the addition of SrCl2, or MgCl2 or MnCl2 to the dialysis buffer. Protein A does not aggregate in the presence of Ca2+, since the s20,w was identical when determined in the presence (1.30S) and absence (1.35S) of CaCl2. By use of a specific antiserum to protein A it was found that protein C [Bennick & Connell (1971) Biochem. J. 123, 455-464] and perhaps minor related components cross-reacted with protein A. No other salivary proteins showed immunological similarity. Proteins A and C were also present in submandibular saliva. The possible functions of protein A are discussed.

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