Biochemical and autoradiographical distribution of hyaluronic acid in calf rib cartilage

Summary In calf rib cartilage, about one half of total hyaluronate is soluble with guanidinium hydrochloride, the other half only after collagenase treatment. Evidence is presented for its pericellular and intracellular distribution.Acknowledgment. This work was supported by grants from the Deutsche Forschungsgemeinschaft (Kl 193/10, Mo 183/5).     

Biochemical and autoradiographical distribution of hyaluronic acid in calf rib cartilage.

In calf rib cartilage, about one half of total hyaluronate is soluble with guanidinium hydrochloride, the other half only after collagenase treatment. Evidence is presented for its pericellular and intracellular distribution.     

Functional role of arginine residues in glutamic acid decarboxylase from brain and bacteria

Summary The arginine-specific reagent phenylglyoxal rapidly inactives glutamic decarboxylase from both mouse brain andE. coli when preincubated with the enzyme at concentrations of 3 mM to 40 mM. The rate of inactivation follows pseudo-first-order kinetics and is dependent upon the concentration of phenylglyoxal. These and other data presented support the idea that arginine residues play a key role in the mechanism of action of glutamic decarboxylase.     

Teratogenic effects of the amino acid leucine in the chicken

Zusammenfassung Leucin wurde in einer Dosis von 0,2 ml einer 1%igen Lösung im Amnion von 9 Tage bebrüteten Hühnereiern injiziert. Morphologische Anomalien mit abnormen Funktionen, meistens in den Beinen und der Nackenregion, wurden beobachtet, während Röntgen-Aufnahmen Stellungsanomalien in Gelenken der Extremitäten und der Halswirbel zeigten.

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This work was aided by grants from Sigrid Juselius Foundation.     

Functional role of arginine residues in glutamic acid decarboxylase from brain and bacteria.

The arginine-specific reagent phenylglyoxal rapidly inactives glutamic decarboxylase from both mouse brain and E. coli when preincubated with the enzyme at concentrations of 3 mM to 40 mM. The rate of inactivation follows pseudo-first-order kinetics and is dependent upon the concentration of phenylglyoxal. These and other data presented support the idea that arginine residues play a key role in the mechanism of action of glutamic decarboxylase.     

Expansion of amino acid homo-sequences in proteins: Insights into the role of amino acid homo-polymers and of the protein context in aggregation

Expansion of amino acid homo-sequences, such as polyglutamines or polyalanines, in proteins has been directly implicated in various degenerative diseases through a mechanism of protein misfolding and aggregation. However, it is still unclear how the nature of the expansion and the protein context influence the tendency of a protein to aggregate. Here, we have addressed these questions using spinocerebellar ataxia type-3 (ATX3) protein, the best characterised of the polyglutamine proteins, chosen as a model system. Using a transfected mammalian cell line, we demonstrate that ATX3 aggregation is noticeably reduced by deletion or replacement of regions other than the polyglutamine tract. The nature of the amino acid homo-sequences also has a strong influence on aggregation. From our studies, we draw general conclusions on the effect of the protein architecture and of the amino acid homo-sequence on pathology. Received 3 March 2006; received after revision 19 April 2006; accepted 22 May 2006     

Structure of albizziine [L(-)-2-amino-3-ureidopropionic acid], an amino acid from higher plants(Mimosaceae)

Zusammenfassung Eine neue Aminosäure, Albizziin, wurde durch chemische Verknüpfung zwischen N-Benzoylalbizziinmethylester undl-2-Benzamido-3-ureidopropionsäuremethylester (III) alsl-2-Amino-3-ureidopropionsäure (I) identifiziert. Die Synthese vonl-2-Ureido-3-aminopropionsäure (II) wird beschrieben.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution

Summary The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the postinvolution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.Supported by the University Grants Commission, Govt of India under the scheme Support to Research.     

Mass spectrometric determination of the amino acid sequence in arginine-containing peptides

aa, a-a a- a aa - aa a -a .     

Structure and evolution of the genetic code viewed from the perspective of the experimentally expanded amino acid repertoire in vivo

Much effort has been devoted recently to expanding the amino acid repertoire in protein biosynthesis in vivo. From such experimental work it has emerged that some of the non-canonical amino acids are accepted by the cellular translational machinery while others are not, i.e. we have learned that some determinants must exist and that they can even be anticipated. Here, we propose a conceptual framework by which it should be possible to assess deeper levels of the structure of the genetic code, and based on this experiment to understand its evolution and establishment. First, we propose a standardised repertoire of 20 amino acids as a basic set of conserved building blocks in protein biosynthesis in living cells to be the main criteria for genetic code structure and evolutionary considerations. Second, based on such argumentation, we postulate the structure and evolution of the genetic code in the form of three general statements: (i) the nature of the genetic code is deterministic; (ii) the genetic code is conserved and universal; (iii) the genetic code is the oldest known level of complexity in the evolution of living organisms that is accessible to our direct observation and experimental manipulations. Such statements are discussed as our working hypotheses that are experimentally tested by recent findings in the field of expanded amino acid repertoire in vivo. Received 30 June 1999; accepted 9 July 1999