The free amino acid composition of human saliva

The quantitative free amino acid composition of whole saliva and parotid and submaxillary secretions collected on 3 or 4 separate days was determined in three individuals. Free amino acids were determined semiquantitatively in the whole saliva of six individuals collected on 10 separate days over a period of 3 weeks. Eighteen free amino acids were found in whole saliva, with the concentration of some amino acids varying considerably in individual salivas. Six amino acids were found consistently and three inconsistently and in very small quantities in parotid secretions. Twelve amino acids were found regularly and two irregularly in submaxillary secretions. A comparison of whole saliva and submaxillary secretion from an individual indicates that approximately one-half of the free amino acids in whole saliva are submaxillary in origin. The ammonia nitrogen, amino nitrogen and total nitrogen were determined in the whole saliva of six individuals.     

猪釉基质蛋白的提取及N末端氨基酸序列分析

目的：从猪牙胚提取釉基质蛋白并做氨基酸测序,为进一步研究釉基质蛋白诱导牙周组织再生的生物活性奠定基础。方法：选择乙酸提取法获得釉基质蛋白,采用ＳＤＳ－ＰＡＧＥ电泳和印迹膜测序法分析Ｎ末端氨基酸序列。结果：提取的釉基质蛋白分子量条带主要位于２０ＫＤａ以下,优势条带为２０ＫＤａ、１３ＫＤａ、５ＫＤａ。２０ＫＤａ、５ＫＤａ釉基质蛋白Ｎ末端前１０个氨基酸残基均为：Ｍｅｔ、Ｐｒｏ、Ｌｅｕ、Ｐｒｏ、Ｐｒｏ、Ｈｉｓ、Ｐｒｏ、Ｇｌｙ、Ｈｉｓ、Ｐｒｏ。结论：乙酸提取法可获得典型的釉原蛋白。印迹膜测序法简易、快速、敏感。     

Changing amino acid profiles of developing dental enamel in individual human teeth and the comparison of the protein matrix of developing human and bovine enamel

Chemical and electrophoretic studies of dental enamel matrix proteins isolated from developing human incisors showed that the human enamel matrix, although having an overall amino acid composition similar to bovine developing enamel, showed some differences in its electrophoretic patterns. The amino acid compositions of enamel removed sequentially from the labial tooth surfaces had increasing proportions of aspartic acid, serine, glycine, alanine and lysine with increased degree of mineralization.     

Molecular composition of the protein matrix of developing human dental enamel

The protein matrix of fetal human dental enamel was isolated and fractionated by chromatographic and electrophoretic procedures. Nine principal protein fractions were isolated and characterized. Possible inter-relationships of these proteins and their comparison with data from other species were examined. Significant differences between human proteins and those described for cow or pig enamel were identified.     

Amino acid composition,distribution and origin of “tuft” protein in human and bovine dental enamel

Protein with a composition resembling that of the “tuft” protein, previously described only in the enamel of mature human molars, has been isolated from different types of mature permanent and deciduous human and bovine teeth. A protein fraction not dissimilar from tuft protein in composition has also been obtained from developing enamel.     

Human salivary alpha-amylase Purification and amino acid composition

Abstract— Human salivary alpha-amylase was purified by ammonium sulfate-acetone precipitations, and residual impurities removed by adsorption chromatography on hydroxylapatite columns. Subsequent preparative disc electrophoresis indicated that parotid alpha-amylase from one person was a single moiety, whereas alpha-amylase from pooled, whole saliva was separated into two components. One of these had the same electrophoretic mobility as the parotid alpha-amylase. The amino acid compositions of these components were determined and compared with monkey and rabbit parotid alpha-amylase and with the results of an earlier investigation of human alpha-amylase from pooled, whole saliva. Significant differences were not observed.     

牛牙骨质附着蛋白N末端氨基酸序列分析

目的 :对牛牙骨质附着蛋白进行N末端氨基酸序列分析 ,为牙骨质附着蛋白的克隆表达提供一定的理论依据。方法 :应用乙酸和盐酸胍提取法获取牛牙骨质附着蛋白 ,鉴定纯度后进行N末端氨基酸序列分析。结果 :所获得的牛牙骨质附着蛋白纯度 >95 % ,N末端 15个氨基酸残基为 :Ile、Pro、Leu、Asp、Pro、Val、Ala、Gly、Cys、Lys、Glu、Pro、Ala、Ala、Asp。 结论 :测得的氨基酸序列具有特异性。     

The chemical composition of tooth enamel in junctional epidermolysis bullosa

The junctionalis form of epidermolysis bullosa (EBJ) is associated with a number of clinical problems involving tooth enamel, including increased susceptibility to caries. The aim here was to carry out a chemical characterization of the enamel of teeth from EBJ patients compared with that of unaffected controls. The results showed that while protein concentration, amino acid composition and carbonate content were similar in both groups, EBJ enamel contained a significantly reduced mineral per volume content, resulting in enamel hypoplasia. In addition, Western blotting revealed the presence of serum albumin (a known inhibitor of enamel crystal growth) in EBJ enamel. This was not detected in control enamel or in enamel of teeth from patients with the dystrophic form of the disease. It is concluded that EBJ enamel is developmentally compromised and that the enamel defects are commensurate with the reported genetic lesions.     

Molecular weight and amino acid composition of Macaca irus parotid alpha-amylase

abstract – Parotid alpha-amylase from Macaca irus monkey was obtained by cultivation of glandular tissue in vitro. Gel filtration of the unpurified amylase on Sephadex® and Bio-Gel® columns, using reference proteins, showed a molecular weight of the amylase below 18,000, whereas ultracentrifugation of the crystalline enzyme indicated about 54,000. These values were consistent with the corresponding human amylase, the discrepancy in molecular weight being explained by charge phenomena between the gel matrix and the amylase molecules, causing retardation on the gel filtration columns. The minimum molecular weight according to the amino acid composition was determined to 28,000. Amino acid analysis of the crystalline Macaca irus parotid alpha-amylase showed characteristics very similar to the human parotid amylase, with high amounts of aspartic acid and glycine, and small amounts of the sulfur-containing amino acids. No hexosamines were found. Purification of the parotid amylase from Cercopithecus aethiops monkey indicated different molecular parameters. These findings support the belief that the Macaca irus monkey is well suited as an experimental animal in dental research.     

The amino acid composition of Streptococcus mutans and its culture medium supplemented with xylitol.

The amino and keto acid composition of the cells of Streptococcus mutans, strain Ingbritt, maintained and grown on a Trypticase-Phytone based medium without any added carbohydrate or supplemented with xylitol or glucose, was analyzed. The results showed no remarkable differences in the portions of individual amino acids liberated by acid hydrolysis from the cellular proteins of cells grown in the above mentioned media. However, the amount of free amino acids in the water extracts of the cells grown in the glucose medium differed considerably from those obtained from cells grown in the two other media. The amounts of free amino acids of the medium at the end of the growth period were higher in the glucose containing medium than in the two other media. The content of keto acids was lower in the cells grown in the presence of xylitol or without added carbohydrate when compared to those cells grown in glucose containing medium.