Sweat Proteins Research Articles

Subpicogram analysis of sweat proteins using two-dimensional polyacrylamide gel electrophoresis

Sweat collected from six normal volunteers was analyzed to determine if reproducible protein patterns could be obtained using two-dimensional polyacrylamide gel electrophoresis of 125I-labeled sweat proteins. This method has the capability of easily detecting picogram quantities of protein. Once the methods of collection of the sweat had been standardized, reproducible patterns were obtained from these volunteers. Over 100 discrete spots were revealed by a combination of fluorography and rare earth screen radioautography of dried two-dimensional gels. This method will allow analysis of sweat for qualitative and quantitative variations in protein content in pathologic conditions such as cystic fibrosis, renal failure, and diabetes.

An investigation into the proteins of horse sweat ( Equus caballus)

1. 1. Equine sweat has a high protein content which was previously thought to consist mostly of serum albumin. 2. 2. Investigation of adrenaline and heat-induced equine sweat has now revealed that serum albumin contributes less than 1% to the total secreted protein. 3. 3. The major equine sweat protein consists of two groups of differing molecular weight, the greater of which was glycosylated. 4. 4. The major sweat proteins had low isoelectric points.

Total free amino acids, ammonia, and protein in the sweat of children

The concentrations of total free amino acids, ammonia, and protein in sweat of 44 children, 20 males, and 24 females, 6 to 8 years old, were determined. The children were divided into three groups according to their height, weight, and body weight/height ratio; group I children had heights and weights below the 10th percentile for their age, group II had heights and weights between the 10th and 90th percentile, and group III had heights and weights above the 90th percentile. Sweating was induced by allowing the child to be moderately active. The temperature at the time of the experiment was 31 to 33C and the relative humidity 48%. The mean concentrations of total free amino acids (mg/100 ml) in sweat from groups I, II, and III children were 318.9 ± 52.5, 293.9 ± 82.9 and 265.1 ± 57.0, respectively. Alanine, glycine, phenylalanine, threonine, and serine were the principal amino acids in sweat. The concentrations of ammonia in the sweat of group I, II, and HI children were 6.90 ± 2.97, 2.35 ± 0.81, and 1.17 ± 0.48 mg/100 ml, respectively. Protein concentrations were 44.15 ± 14.07, 40.70 ± 16.60, and 35.75 ± 5.46 mg/100 ml, respectively.

Ultramicro-electrophoresis of protein in sweat from patients with cystic fibrosis of the pancreas and controls.

46 sweat-samples from 32 children with cystic fibrosis of the pancreas (C.F.) and 35 samples from 23 control-children were collected with glass micro-capillaries. Protein was determined by ultramicro-electrophoresis. 1. Protein was detected in 48% of the samples (C.F. and controls). 2. At pH 2.3, C.F.-sweat showed at least one more band than control-sweat. 3. At pH 8.9, C.F.-sweat occasionally showed one more band than the control-group. 4. At pH 2.3, more protein was found at the electrophoresis start point using C.F.-sweat, whereas at pH 8.9 the opposite was found. 5. At pH 2.3, protein was found in fewer samples than at pH 8.9. The "C.F.-factor" is postulated to represent a basic polyelectrolyte which induces the following pathogenic mechanisms: a) Aggregation of proteins giving rise to a high viscosity of secretions, such as saliva. b) Binding to the cell-membrane of the glandular epithelium, thus inducing a disturbance of active NaCl-reabsorption (e.g. by reduction of luminal passive Na+-influx).

Immunological studies on the proteins of human eccrine sweat.

Proteins present in the eccrine sweat collected from the skin surface of male volunteers were studied. The protein content ranged from 0.154--0.774 g per liter. A total 2282 ml sweat was concentrated until a final protein content of 25 mg/ml was reached. Paper electrophoresis revealed 3 fractions migrating like alpha-, beta-, and gamma-globulins. Eight different proteins were demonstrated by immunoelectrophoretic analyses using rabbit antisera directed against human sweat proteins. Three of these proteins were identified as blood serum proteins. One of the remaining 5 proteins could be of epidermal origin; another one which occurs in comedones as well as in sweat seems to be eluted from the sebum film present on the skin surface.

Sweat proteins.

The electrophoretic patterns of skin washings from the calf, sheep, goat, pig, horse and man have been compared. It was concluded that protein in these washings was derived mainly from sweat. The amounts of protein lost and the nature of the proteins in the sweat differed markedly between species. The horse had relatively the highest protein loss during active sweating and man the lowest. The potential biological role of these sweat proteins is discussed, including the possibility that they may provide the animal with an outer defence, on the skin surface, against invasion by foreign organisms.

Micro-isoelectric focusing of proteins in pilocarpineinduced sweat

A micro-technique of isoelectric focusing in polyacrylamide gel in combination with immunodiffusion was used for the separation and characterization of protein components present in low concentration in native sweat obtained by local stimulation of eccrine sweat glands using pilocarpine by iontophoresis. Protein components, mostly of glycoprotein character belonging to the serum Zn- α 2-glycoproteins and the “specific” components were found to be present in pilocarpine sweat; molecular variants of some sweat glycoproteins are assumed to be separated. Micro-gel electrofocusing and immunoelectrofocusing of sweat proteins might be useful for the clinical study of mucoviscidosis and other disorders associated with anomalies in sweat secretion.

An alpha-2 globulin component absent in serum of human foetuses.

WHEN studying specific antigenic properties of sweat proteins using rabbit immune serum against sweat proteins, we have found sweat protein to consist of several components, some of which correspond to serum components whereas the others are most probably of a specific origin1,2. In an attempt to define the serum protein components in sweat, immunoelectrophoresis of normal human serum with rabbit immune serum against sweat proteins was one of the methods used. In these experiments we observed qualitative differences in the immuno-electrophoretic precipitation pattern of a normal serum of adults in comparison with that of foetuses.

Technique of sweat collection in localised sweating by pilocarpine iontophoresis

A technique for the collection of sweat produced by local pilocarpine iontophoresis using glass capillaries is described. Experience with this technique in children as well as in adults is presented. Apart from the estimation of sweat electrolytes the method is especially convenient for the immunochemical analysis of sweat proteins. Its use as a standard method for the collection of sweat for chemical analysis is recommended.