Of 1100 blood donations tested during a prospective study of post-transfusion non-A, non-B hepatitis (NANBH), 6 (0.55%) were repeatedly reactive in a commercial assay for antibodies to the C100 protein of hepatitis C virus. Only 1 of the 6 donations (17%) transmitted NANBH to a recipient. Hepatitis C virus RNA sequences were detected in the serum of the transmitting donor by an assay which used the polymerase chain reaction (PCR) and non-radioisotopic detection. No such sequences were detected in the other 5 donors positive for anti-C100. Stored serum samples from blood donors who had been involved in three episodes of post-transfusion NANBH in 1981 also contained hepatitis C viral sequences. Although the PCR assay in its present form is not suitable for mass donor screening, the presence of hepatitis C viral sequences detected by PCR in blood donations seems a better predictor of infectivity than the presence of anti-C100 alone.

Antigens, Viral↗

PubMed1990

Topographical localization of peroxisomal acyl-CoA ligases: differential localization of palmitoyl-CoA and lignoceroyl-CoA ligases.

We found that peroxisomal lignoceroyl-CoA ligase, like palmitoyl-CoA ligase, is present in the peroxisomal membrane whereas the peroxisomal beta-oxidation enzyme system is localized in the matrix. To further define the role of peroxisomal acyl-CoA ligases (membrane component) in providing acyl-CoA for peroxisomal beta-oxidation, we examined the transverse topographical localization of enzymatic sites of palmitoyl-CoA and lignoceroyl-CoA ligases in the peroxisomal membranes. The disruption of peroxisomes by various techniques resulted in the release of a "latent" pool of lignoceroyl-CoA ligase activity while palmitoyl-CoA ligase activity remained the same. Proteolytic enzyme treatment inhibited palmitoyl-CoA ligase activity in intact peroxisomes but had no effect on lignoceroyl-CoA ligase activity. Lignoceroyl-CoA ligase activity was inhibited only if peroxisomes were disrupted with detergent before trypsin treatment. Antibodies to palmitoyl-CoA ligase and to peroxisomal membrane proteins (PMP) inhibited palmitoyl-CoA ligase in intact peroxisomes, and no pool of "latent" activity appeared when antibody-treated peroxisomes were disrupted with detergent. On the other hand, disruption of PMP antibody-treated peroxisomes with detergent resulted in the appearance of a "latent" pool of lignoceroyl-CoA ligase activity. These results demonstrate that the enzymatic site of palmitoyl-CoA ligase is on the cytoplasmic surface whereas that for lignoceroyl-CoA ligase is on the luminal surface of peroxisomal membranes. This implies that palmitoyl-CoA is synthesized on the cytoplasmic surface and is then transferred to the matrix through the peroxisomal membrane for beta-oxidation in the matrix.(ABSTRACT TRUNCATED AT 250 WORDS)

Acyl Coenzyme A↗

PubMed1990