An endoplasmic reticulum fraction from pig liver enriched in transitional endoplasmic reticulum vesicles capable of forming 50-60 nm buds in the presence of ATP and retinol was assayed for retinol-responsive oxidation of NADH and cleavage of a dithiodipyridine (DTDP) protein disulfide-thiol interchange substrate. Maxima for the two activities alternated giving rise to a 24 min period. The NADH ...

Niemann-Pick type C (NPC) disease is an autosomal recessive lysosomal trafficking disorder, in which the cholesterols are abnormally accumulated in lysosomes. Recently, the β-cyclodextrin (CD) derivatives are revealed to show therapeutic effect for NPC disease through the removal of accumulated cholesterols in lysosomes. Herein, to enhance the therapeutic effect and reduce the toxicity of β-CD ...

This report describes an integrated investigation of the refolding and reductive unfolding of insulin-like growth factor (IGF-I) and its variant, long R IGF-I (LRIGF-I), which has a Glu to Arg substitution and a hydrophobic 13-amino acid N-terminal extension. The refolding performed in glutathione redox buffer was quenched at different time points by adjusting the pH to 2.0–3.0 with a 1 N HCl s...

The formation of striped phases of dialkyl disulfides on Au(111) and graphite has been monitored by scanning tunneling microscopy (STM). STM imaging clearly exhibits the formation of striped phases having corrugation periodicities that are nearly consistent with the molecular length of alkanethiolate moieties formed after the S-S bond cleavage of dialkyl disulfide on a gold surface. This is the...

The reaction of 2,6-diformyl-4-methylphenyl disulfide with [Ni(tn)3]Cl2 (tn = 1,3-diaminopropane), in methanol and the presence NaBPh4 resulted isolation [Ni2(L1)](DMF)2(BPh4)2 (I), (L1 15,95-dimethyl-3,7,11,15-tetraaza-1,9(1,3)-dibenzenacyclohexadecaphane-2,7,10,15-tetraene-12,92-bis(thiolate). This represents a 2-electron solvent assisted reduction bond to form two thiolate ligands where is c...

Hirudin is a 65-amino acid polypeptide with three disulfide linkages. It is stable under extreme pH (1.4712.9), high temperature (95 “C), and in the presence of denaturants (6 M guanidinium chloride or 8 M urea). The thrombin inhibitory activity of hirudin remains unaffected even after cleavage of an internal peptide bond ( L y ~ ~ ‘ A s n ~ ~ ) . One condition which effectively and irreversibl...

The von Willebrand factor (VWF) A2 crystal structure has revealed the presence of a rare vicinal disulfide bond between C1669 and C1670, predicted to influence domain unfolding required for proteolysis by ADAMTS13. We prepared VWF A2 domain fragments with (A2-VicCC, residues 1473-1670) and without the vicinal disulfide bond (A2-DeltaCC, residues 1473-1668). Compared with A2-DeltaCC, A2-VicCC ex...

Virgin soybean trypsin inhibitor has 1 NHp-terminal aspartic acid or asparagine residue and no COOH-terminal residues that can be released by carboxypeptidase B. Upon incubation with 1 mole % of trypsin for 24 hours at pH 3.75, virgin inhibitor is converted to a modified inhibitor which has 2 NH2 terminals aspartic acid or asparagine and isoleucine. Approximately 1 mole of arginine is released ...

Employing mercaptoethylamine as a reducing agent, it was demonstrated by analytical ultracentrifugation and polyacrylamide gel electrophoresis that polymeric immunoglobulin A (IgA) was reduced to a 10 S dimer and 7 S monomer, and that dimer IgA was more resistant to reductive cleavage than the higher polymers. When dimer and monomer IgA were subjected to electrophoresis in polyacrylamide gels i...

It is essential to bear in mind that the native conformation of human proteins is stabilized by intra-molecular disulfide (S–S) bonds between a single or multiple polypeptide chains. The formation of S–S bonds is catalyzed by protein disulfide isomerase (PDI) (1), the activation of which is associated with a number of human diseases, such as myocardial infarction, stroke, and cancer. Unless pro...