Twenty-five gene products of bacteriophage BF23 were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their functions were studied in relation to type I and II genes classified by means of genetic complementation tests. AU the type I mutants were defective in the synthesis of a tail protein, L3. In addition, 4 type I gene products, L5 (gp21), L7 (gp2O), L8 (gp29), and L9 (gp25), were identified as constituents of tails (gp21 denotes that a protein is a product of gene 21). Three type Ilb mutants in genes 10, 14, and 19 diminished substantially the production of late proteins, including tail and head proteins, and the two other type Ilb mutants in genes 1 and 2 were defective in the synthesis of both early and late proteins. Of 14 type IIa mutants, at least 6 were defective in phage DNA synthesis and 2 were defective in the synthesis of head proteins. The defect in the head donor activities of type Ila mutants in extract complementation tests was due to the failure of the formation of mature heads containing DNA. The above results support directly the results of the genetic characterization of BF23 genes.

The cationic ring‐opening polymerization of 1,6‐anhydro‐2,3,4‐tri‐0‐benzyl‐β‐D‐altropyranose (TBLAT, M2) failed to give the fourth stereoregular 1,6‐α‐linked polysaccharide because of its very low homopolymerizability. However, the 1,6‐anhydro‐altrose monomer was found to copolymerize with 1,6‐anhydro‐2,3,4‐tri‐0‐(p‐methylbenzyl)‐β‐D‐glucopyranose (LGTXE, M1) with PF5 as catalyst at low temperature, giving highly stereoregular copolymers. The monomer reactivity ratios calculated by Kelen‐Tüdös method were r1 = 1.52 and r2 = 0.06. The differences in the reactivity between TBLAT monomer and other 1,6‐anhydro sugar derivatives are discussed. Moreover, 1,6‐anhy‐dro‐2‐0‐benzyl‐3,4‐0‐isopropylidene‐β‐D‐galactopyranose (ABIGA, M4), which showed no homopolymerizability under various conditions, was also copolymerized with 1,6‐anhydro‐2,3,4‐tri‐0‐benzyl‐β‐D‐glucopyranose (LGTBE, M3) at low temperature. The monomer reactivity ratios of r3 = 2.2 and r4 = 0.0 indicate that in the copolymers every galactose unit distributed as a single unit through the main chain. The cause for the lower polymerizability of ABIGA is discussed. Hydrolysis of the copolymer with trifluoroacetic acid gave a copolymer in which only galactose units contained free hydroxyl groups, which were then methylated by methyl iodide. Stereoregular 1,6‐α‐linked galactoglucan composed of free sugar units was prepared by debenzylation of the ABIGA‐LGTBE copolymer followed by hydrolysis.

Extensive screening of the mitogens lipopolysaccharide (LPS), pokeweed mitogen (PWM), and Staphylococcus aureus Cowan I (SAC I), alone and in combination and with and without interleukin (IL) was performed for in vitro activation of regional lymph node lymphocytes from lung cancer patients for the production of human IgG, IgM, and IgA. As assessed by electrofusion of the lymphocytes following their exposure to these agents with mouse myeloma cells and incubation of the fused hybridoma, a remarkable stimulatory effect was shown by LPS and particularly by LPS plus IL-4, which was substantially greater than that of either SAC I or PWM with or without various IL. Optimization studies indicated that the addition of PWM to LPS and IL-4 in the culture medium further stimulated the human antibody (Ab) production, and that the optimal formulation for stimulation of human IgG production was a culture medium containing 20 micrograms/ml of LPS, 1/500 of PWM, and 100 u/ml of IL-4.

Regulation of temporal synthesis of pre-early, early, and late proteins in bacteriophage BF23-infected cells has been studied by using five amber mutants defective in genes 1, 2, 10, 14, and 19. The synthesis of pre-early proteins is negatively regulated by the actions of gene 1, a pre-early gene. The switch from pre-early to early protein synthesis is mainly regulated by the second-step DNA transfer reaction, which is controlled by at least genes 1 and 2. Early proteins can be kinetically and genetically divided into two regulatory classes, designated Ea and Eb. The shutoff of Eb-early protein synthesis is associated with the turn-on of late protein synthesis. This step is controlled by genes 10, 14, and 19. Gene 10 also regulates negatively the synthesis of Ea-early proteins, indicating that this gene has a dual function in the regulation of early protein synthesis. The temporal synthesis of phage-encoded proteins is regulated mainly at the transcriptional level. Evidence is presented indicating that the host RNA polymerase is modified by the interaction with the gene products of genes 2, 10, and 14 (gp2, gplO, and gp14, respectively). gp2 interacts with the enzyme in the earlier stage of infection but is replaced by gplO in the later stage. This exchange reaction depends on the presence of gp14 and gpl9 and is related to the switch from Eb to late protein synthesis. Thus, the regulation of BF23 gene expression occurs in a coordinated manner throughout the development of this phage.

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