Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lymphocyte function-associated antigen 1 (LFA-1) was immunoprecipitated from various types of surface-radioiodinated murine lymphocytes, and analyzed by two-dimensional polyacrylamide gel electrophoresis. LFA-1 alpha and beta chains from splenic B lymphocytes had the same apparent molecular weights as, but distinct isoelectrofocusing patterns from, their counterparts from thymocytes or splenic T lymphocytes. The splenic B lymphocytes lacked a basically charged population of alpha chain, while the thymocytes and the splenic T lymphocytes showed both the acidic and the basic portions. Furthermore, the beta chain of the former migrated more towards the acidic end than that of the latter. No difference was found between LFA-1 molecules of the same lineage of cells from several strains of mice whose H-2 haplotypes were different from one another. When murine lymphocyte lines were examined, LFA-1 with various isoelectrofocusing patterns were recognized. The charge difference again reflected the difference in lymphocyte lineage, but in a more exaggerated manner than that seen with cells from mice. The average acidity of both chains of LFA-1 decreased in the order of B cell lines, pre-B cell lines and T cell lines. The lineage-dependent charge difference of either chain disappeared after neuraminidase treatment of LFA-1, indicating that lymphocyte differentiation was accompanied by changes in LFA-1 sialylation.
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PMID:Sialylation patterns of lymphocyte function-associated antigen 1 (LFA-1) differ between T and B lymphocytes. 354 27

This study concerned the resolution of rat pituitary FSH utilizing chromatofocusing. Among the 11 components resolved and positively identified, ten had apparent isoelectric points (pI) between 3.1 and 5.1. Approximately 1% of pituitary FSH eluted at pH 9.4. Treatment with varying amounts of neuraminidase followed by refocusing generated FSH components of higher pI values. Treatment with other glycosidases did not alter the elution characteristics in chromatofocusing, while exclusion chromatography established an inverse relationship between apparent molecular weight and pI. Dose-response curves of various FSH components and of the reference preparation in the current radioimmunoassay system were parallel to each other. A study of their in-vitro bioactivity, utilizing granulosa cells which produce a plasminogen activator due to FSH in a dose-dependent manner, provided the following evidence: increased acidity of the components led to an increase of maximum response and an increase of the dose necessary for half-maximum response. Considering the observed alterations in the heterogeneity of FSH with changing physiological states of the animal, it is concluded that qualitative changes of the FSH molecule are perhaps involved in a modulatory role in the biopotencies of the hormone.
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PMID:Heterogeneity of rat FSH by chromatofocusing: studies on in-vitro bioactivity of pituitary FSH forms and effect of neuraminidase treatment. 392 42

Thermostability studies have been performed at different preincubation temperatures (37-65 degrees C) on human alpha-L-fucosidase (alpha-L-fucoside fucohydrolase, EC 3.2.1.51), purified serum and liver enzyme, the isoelectric forms of purified liver enzyme which were separated by preparative isoelectric focusing, crude adult and fetal liver supernatant enzyme and neuraminidase-treated enzyme. Very different thermostability curves were found for the various isoelectric forms of alpha-L-fucosidase. The most neutral form (I) is least thermostable and the most acidic form (VIII) most thermostable, with the intervening forms (II-VII) having intermediate thermostabilities. For the isoelectric forms of liver alpha-L-fucosidase there appars to be a significant trend of increasing thermostability with increasing acidity (and presumably, increasing amounts of sialic acid). In order to determine what role, if any, sialic acid plays in determining the thermostability of alpha-L-fucosidase, comparative thermostability studies were performed on alpha-L-fucosidases from different human tissues which are reported to contain varying amounts of sialic acid. The purified sialic acid-rich serum enzyme is considerably more thermostable than the purified liver enzyme. The fetal liver enzyme (which is less acidic and may contain less sialic acid than the adult liver enzyme) is less thermostable than adult liver alpha-L-fucosidase. In contrast to all of the above findings which suggest that sialic acid confers thermostability to alpha-L-fucosidase, neuraminidase treatment of human liver alpha-L-fucosidase did not change its thermostability, even when considerable desialylation occurred as monitored by isoelectric focusing. The reason for these apparently inconsistent findings is not clear at the present time but several possible interpretations of the data are given.
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PMID:Thermostability of human alpha-L-fucosidase. Relationship to fucosidosis and low-activity serum alpha-L-fucosidase. 740 97

As measured by fluid accumulation in ileal loops, Vibrio cholerae mucinase complex, with or without toxoid, protected guinea pigs from challenges with V. cholerae live organisms and enterotoxin. The neuraminidase and proteinases of the complex were combined in modified oil emulsion or aluminum hydroxide adjuvants and the resultant vaccines given by the parenteral or oral routes. There was little difference between the two types of adjuvant. Control of stomach acidity improved oral vaccination. Animals injected intramuscularly (i.m.) with toxoid-containing vaccines were protected from challenge with cholera toxin (CT) whereas those given oral doses were not. Toxoid plus killed V. cholerae cells elicited a more effective protection against toxin challenge than killed V. cholerae cells alone. Vaccines containing mucinases, with or without toxoid, protected the animals from a live V. cholerae challenge. The anti-mucinase immune response may prevent adhesion of the V. cholerae cells and hence reduce delivery of toxin to receptors. These mucinases, neuraminidase and proteinases, may be useful components of acellular, toxoided cholera vaccines for human immunisation.
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PMID:Experimental immunisation and protection of guinea pigs with Vibrio cholerae toxoid and mucinases, neuraminidase and proteinase. 1514 70

A sensitive and efficient method using high-performance CE (HPCE) and neuraminidase hydrolysis was developed to study the lactonization and hydrolysis of alpha2,8-pentasialic acid. Eleven lactone species of pentasialic acid formed in glacial acetic acid were detected and classified into three groups based on the number of carboxylic acids: monolactones with four carboxylic acids, dilactones with three carboxylic acids, and trilactones with two carboxylic acids. These lactones eluted between the original pentamer (with five carboxylic acids) and the fully lactonized species (with one carboxylic acid) in HPCE. Eight of the isomers were identified by hydrolysis with neuraminodase. Results obtained from previous reports and from this study together reveal a general rule for predicting the subtle difference in the acidity of each carboxylic acid in oligosialic acids: the closer the carboxylic acid is to the nonreducing end, the more acidic it is. Therefore, the elution order of lactone isomers having the same number of carboxylic groups can be predicted from the position of the free carboxylic groups in pentasialic acid. We used this principle and the results of hydrolysis with neuraminidase to identify hexamer lactone isomers separated by HPCE.
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PMID:High-performance CE: an effective method to study lactonization of alpha2,8-linked oligosialic acid. 1705 86