Novel Direct Assay for Acetyl-CoA:α-Glucosaminide N-Acetyltransferase Using BODIPY-Glucosamine as a Substrate.

Heparan sulfate acetyl-CoA:α-glucosaminide N-acetyltransferase (HGSNAT) catalyzes the transmembrane acetylation of heparan sulfate in lysosomes required for its further catabolism. Inherited deficiency of HGSNAT in humans results in lysosomal storage of heparan sulfate and causes severe neurodegenerative disease, mucopolysaccharidosis III type C (MPS IIIC). MPS IIIC patients can potentially benefit from a therapeutic approach based on active site-specific inhibitors of HGSNAT used as pharmacological chaperons to modify the folding of the mutant protein in the patient's cells.

High stability of the hinge region in the membrane-active peptide helix of zervamicin: paramagnetic relaxation enhancement studies.

Zervamicin IIB is a 16 amino acid peptaibol that forms voltage dependent ion channels with multilevel conductance states in planar lipid bilayers and vesicular systems. Stability of the hinge region and intermolecular interactions were investigated in the N- and C-terminally spin-labelled peptide analogues. Intermolecular and intramolecular paramagnetic enhancement indicates that zervamicin behaves as a rigid helical rod in methanol solution.

Influenza A hemagglutinin C-terminal anchoring peptide: identification and mass spectrometric study.

MALDI-TOF MS and N-terminal amino acid sequencing allowed us to identify several fragments of the C-terminal peptide of Influenza A hemagglutinin (HA) containing transmembrane domains (TMD). These fragments were detected in the organic phase of chloroform-methanol extracts from bromelain-treated virus particles. Heterogeneous fatty acylation of the C-terminus was revealed.

Biosynthetic uniform 13C,15N-labelling of zervamicin IIB. Complete 13C and 15N NMR assignment.

Zervamicin IIB is a member of the alpha-aminoisobutyric acid containing peptaibol antibiotics. A new procedure for the biosynthetic preparation of the uniformly 13C- and 15N-enriched peptaibol is described This compound was isolated from the biomass of the fungus-producer Emericellopsis salmosynnemata strain 336 IMI 58330 obtained upon cultivation in the totally 13C, 15N-labelled complete medium. To prepare such a medium the autolysed biomass and the exopolysaccharides of the obligate methylotrophic bacterium Methylobacillus flagellatus KT were used.

Domain structure and ATP-induced conformational changes in Escherichia coli protease Lon revealed by limited proteolysis and autolysis.

Escherichia coli protease Lon (La) is an adenosine triphosphate (ATP)-regulated homo-oligomeric proteolytic complex responsible for the recognition and selective degradation of abnormal and unstable proteins. Each subunit of the protease Lon appears to consist of three functional domains: the C-terminal proteolytic containing a serine active site, the central displaying the ATPase activity, and the N-terminal with still obscure function. We have used limited proteolysis to probe the domain structure and nucleotide-induced conformational changes in the enzyme.