Human parotid saliva protein composition: dependence on physiological factors

1982 ◽  
Vol 242 (3) ◽  
pp. G231-G236 ◽  
Author(s):  
S. G. Oberg ◽  
K. T. Izutsu ◽  
E. L. Truelove

The relative concentrations of the major proteins in human parotid saliva as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis varied greatly between the six individuals included in this study but were remarkably constant for a given individual. Individual relative parotid protein concentrations differed in salivas collected under unstimulated and stimulated conditions but were at least partially independent from circadian and feeding effects. In addition, the relative concentrations of certain salivary proteins decreased with continued lemon-drop stimulation. A total of 29 different bands was composited from the six subjects. Five of the bands had mobilities corresponding with those of calibration proteins selected for their known occurrence in parotid saliva. Only those proteins comprising at least 0.75% of the total protein concentration were detected. Relative protein concentrations of parotid saliva samples collected 12 mo apart from given individuals were identical.

1996 ◽  
Vol 17 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Guy H. Carpenter ◽  
Gordon B. Proctor ◽  
Caroline L. Pankhurst ◽  
Roger W. Linden ◽  
Deepak K. Shori ◽  
...  

1987 ◽  
Vol 66 (2) ◽  
pp. 576-582 ◽  
Author(s):  
D.A. Johnson ◽  
O.F. Alvares ◽  
K.R. Etzel ◽  
D.N. Kalu

Previous studies have shown that several factors — such as alloxan-induced diabetes, adrenalectomy, or removal of the thyroid-parathyroid gland complex — can influence the flow rate, protein concentration, and protein composition of rat parotid saliva. The present study was undertaken to explore further the influence of glucocorticoids and thyroxine on rat parotid saliva in hormonally intact animals. As compared with untreated animals, adult male rats treated with 10 μg dexamethasone per 100 g body weight for eight days demonstrated a 75% reduction in volume of parotid saliva secreted in response to a uniform stimulus. The protein concentration of the saliva was increased three-fold. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed relative decreases in acidic and basic proline-rich proteins and in a protein identified as Fraction V, while amylase was increased. The electron microscopic appearance of the granules was markedly different from that of the control, in that the granules exhibited an electron-dense periphery and core, with the remainder of the granule having an electronlucent appearance. In contrast, rats treated for eight days with 20 μg thyroxine per 100 g body weight exhibited a 50% increase in volume of saliva collected in response to a secretory stimulus. Although the concentration of protein was not different from that of the control, gel electrophoresis showed relative increases in acidic and basic proline-rich proteins and a decrease in Fraction V. Amylase was unchanged. The secretory granules of thyroxine-treated rats were electronlucent and amorphous. The granules appeared to coalesce within the cell. These effects on flow rate, protein concentration, and protein composition which occur in the dexamethasone- or thyroxine-treated groups are opposite those shown to occur following removal of the adrenal or thyroid-parathyroid glands, respectively. In summary, the results indicate that hormones of several endocrine systems are involved in the regulation of salivary flow rate, protein concentration, and protein composition.


2017 ◽  
Vol 3 ◽  
Author(s):  
A. R. Escalona-Montaño ◽  
R. Pérez-Montfort ◽  
N. Cabrera ◽  
R. Mondragón-Flores ◽  
D. E. Vélez-Ramírez ◽  
...  

AbstractThe main goal of this work consisted in cloning, purifying and characterizing a protein phosphatase 2C (PP2C) from promastigotes ofLeishmania major. The gene was cloned and amplified by PCR using specific oligonucleotides and the recombinant protein was purified by affinity chromatography. The peak with maximal protein concentration was analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and revealed a protein of 44·9 kDa with PP2C activity. This activity was dependent on divalent cations (Mg+2and Mn+2) and was optimal at pH of 8·5, using phosphothreonine as the substrate. Sanguinarine inhibited the activity of the recombinantLmPP2C, while protein tyrosine phosphatase inhibitors had no effect. The recombinantLmPP2C was used to generate polyclonal antibodies. These antibodies recognized a protein of 44·9 kDa in differentLeishmaniaspecies; theLmPP2C was localized in the flagellar pocket and the flagellum of promastigotes.


2021 ◽  
Vol 15 (1) ◽  
pp. 27-36
Author(s):  
V. V. Mykhaliuk ◽  
◽  
V. V. Havryliak ◽  

Background. Keratins are natural biopolymers with a wide range of applications in the field of biotechnology. Materials and Methods. Extraction of keratins was performed by a modified Nakamura method using 250 mM DTT. The protein concentration in the supernatant was determined by Bradford method. The protein composition was studied by their electro­phoretic separation in a polyacrylamide gel in the presence of sodium dodecyl sulfate. The films were made by casting. The surface characteristics of the films were determined using a scanning electron microscope REMMA-102. The elemental composition of the films was determined using an X-ray microanalyzer. Results. The protein concentration in the supernatant was 3.75 mg/mL. After using dithiothreitol in the extraction mixture, we obtained proteins of intermediate filaments with a molecular weight of 40–60 kDa and a low Sulfur content. In the low molecular weight region, we obtained keratin-associated proteins with a molecular weight of 10–30 kDa and a high content of Sulfur. These proteins belong to fibrillar proteins, which can be used as a matrix for the creation of new keratin-containing biocomposites with a wide range of applications in reparative medicine and tissue engineering. Based on the obtained keratin extract, polymer films with and without the addition of glycerol were made. Scanning electron microscopy revealed that glycerol provided the film structure with homogeneity and plasticity due to the accumulation of moisture after the fixation by water vapor. The X-ray microanalysis of films revealed such elements as Sodium, Silicon, Sulfur, Potassium. Among the detected elements, Sulfur has the largest share that is due to the large number of disulfide bonds in the keratin molecule. Conclusions. The polymer keratin films with the addition of glycerol demonstrated better mechanical properties and can be used in biomedicine.


2005 ◽  
Vol 2005 ◽  
pp. 198-198
Author(s):  
A. A. Sadeghi ◽  
P. Shawrang ◽  
M. Moradi ◽  
A. Nikkhah

Proteolysis within plant cells occurs during wilting and drying. Changes in plant proteins during those periods usually are monitored by measurement of total crude protein and non protein nitrogen. Alternatively, changes in concentrations of individual proteins can be measured. Plants are composed of an array of different proteins. Electrophoresis can be used to separate these proteins and has been used to study effects of wilting and ensiling on proteins of some forages (Grum et al., 1991). Electrophoresis also has been used in the study of ruminal hydrolysis of oilseed meals proteins (Sadeghi et al., 2004). Most of the experiments designed to use electrophoresis to study protein metabolism in forages and ruminants have been qualitative. The main objective of this study was to determine whether sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometry could be used to monitor quantitatively the changes in alfalfa protein composition during wilting, drying and ruminal exposure.


1974 ◽  
Vol 63 (2) ◽  
pp. 456-465 ◽  
Author(s):  
G. Banker ◽  
L. Churchill ◽  
C. W. Cotman

An analysis was made of the protein composition of a fraction of postsynaptic densities (PSDs) prepared from rat brain. Protein makes up 90% of the material in the PSD fraction. Two major polypeptide fractions are present, based on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The major polypeptide fraction has a molecular weight of 53,000, makes up about 45% of the PSD protein, and comigrates on gels with a major polypeptide of the synaptic plasma membrane. The other polypeptide band has a molecular weight of 97,000, accounts for 17% of the PSD protein, and is not a prominent constituent of other fractions. Six other polypeptides of higher molecular weight (100,000–180,000) are consistently present in small amounts (3–9% each). The PSD fraction contains slightly greater amounts of polar amino acids and proline than the synaptic plasma membrane fraction, but no amino acid is usually prominent. The PSD apparently consists of a structural matrix formed primarily by a single polypeptide or class of polypeptides of 53,000 molecular weight. Small amounts of other specialized proteins are contained within this matrix.


1992 ◽  
Vol 38 (11) ◽  
pp. 1162-1166 ◽  
Author(s):  
Alla S. Kostyukova ◽  
Georgi M. Gongadze ◽  
Anna Ya. Obraztsova ◽  
Konstantin S. Laurinavichus ◽  
Oleg V. Fedorov

Sodium dodecyl sulfate – polyacrylamide gel electrophoresis of flagella from the thermophilic methanogen Methanococcus thermolithotrophicus indicated that they were composed of three major proteins, with molecular weights of 62 000,44 000, and 26 000, whereas all previously studied flagella of mesophilic methanogens consisted of two subunits. Proteins were isolated by preparative electrophoresis followed by complete removal of sodium dodecyl sulfate and their renaturation. It was shown that at least two of the proteins contain a thermostable domain whose complete denaturation proceeds only upon prolonged boiling in the presence of sodium dodecyl sulfate. Key words: flagellin, thermostability, archaebacteria, Methanococcus thermolithotrophicus.


1983 ◽  
Vol 96 (4) ◽  
pp. 1030-1039 ◽  
Author(s):  
W J Brown ◽  
W A Shannon ◽  
W J Snell

The specific and azurophilic granules of rabbit polymorphonuclear heterophils (PMNs) have been isolated and fractionated into membrane and extractable subfractions. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) revealed several features of the protein composition of the two granules: (a) Whereas each type of granule had 40-60 proteins separable on one-dimensional gradient gels, few of the proteins were common to both granules. (b) The proteins of the extractable fractions (which comprised approximately 98% of the total granule protein) of each granule were distinct from the proteins of the membrane fractions (which comprised approximately 2% of the total granule protein). (c) The extractable proteins co-migrated with those collected from the medium of ionophore-treated, degranulating PMNs and therefore were defined as content proteins. These results were confirmed by radiolabeling studies. Lactoperoxidase-catalyzed iodination of intact granules did not label the content proteins but did label proteins that co-migrated with major granule membrane proteins. Moreover, disruption of the granules before iodination led to labeling of both content and membrane proteins. We conclude that the membranes of specific and azurophilic granules, which arise from different faces of the Golgi complex, are composed of unique sets of membrane proteins some of which are exposed on the cytoplasmic face of the granules.


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