Ancovenin, an inhibitor of angiotensin I converting enzyme isolated from the culture broth of a Streptomyces species, is a dialysable peptide composed of sixteen amino acid residues containing unusual amino acids such as threo-;3-methyllanthionine, meso-lanthionine, and dehydroalanine. * In the preliminary tests , the IC50 value of ancovenin to rat lung ACE is 8.5 x 10-8 M, while the values of captopril, MK-422, and potentiator C, a peptidyl inhibitor, are 1.4X10-1m, 3.5x10-1m, and 5.6x10-7M, respectively.

A new inhibitor of angiotensin I converting enzyme, I5B2, was isolated from the culture broth of Actinoinadura sp. No. 937ZE-1. This compound contains N-methylvaline, tyrosine and 1-amino-2-(4-hydroxyphenyl)ethylphosphonic acid. The microorganism also produced another inhibitor, 15131, which is identical with K-4 isolated from Actinnonladura sp. as an antihypertensive agent.

A supersensitive polymerase chain reaction procedure was developed to detect human T-lymphotropic virus type II (HTLV-II) proviral genome. Six primer pairs covering the various regions of HTLV-II were compared and selected on the basis of specificity and sensitivity. Among them, one primer pair of the pol region of HTLV-II (II pol) was able to amplify and detect even 0.1 fg of the cloned plasmid HTLV-II DNA (seven copies) by regular ethidium bromide staining on polyacrylamide gel. By using this procedure, we screened 189 HTLV-I seropositive blood donors from Yamaguchi and Fukuoka Red Cross Blood Centers, Japan. There were four positive samples detectable with the HTLV-II-specific pol primer pair, as well as with the HTLV-I tax primer pair. The amplified DNAs of two specimens were cloned and sequenced. The sequences of the HTLV-I tax region from both specimens were identical to that of HTLV-I. On the other hand, those of the HTLV-II pol region were identical to that of HTLV-II, except for one base substitution in a clone from one subject. These results indicate that dual infection of HTLV-I and HTLV-II in the same persons occurs among Japanese blood donors.

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