field; that purchasers of these products had been denied the benefit of free competition; and that concentration in the chemical industry had been in creased. Such charges, if proved, would violate section 1 of the Sherman Act and section 7 of the Clayton Act. The suit came 10 years after formation of Mobay Chemical. The judgment also orders that within three months after Monsanto's sale of its interest in Mobay, Monsanto "shall not have or allow to serve as an officer or director of Monsanto any in dividual whom it knows to be an offi cer, director or managing agent of Mobay." Similarly, Mobay may not employ any officer or director of Mon santo. The 1964 suit said that "offi cers, directors, and employees of Mo bay have been appointed from among officers, directors, and employees of both Monsanto and Bayer." Bayer and Mobay are prohibited from selling or transferring any of the shares of Mobay or any substantial part of Mobay's isocyanate business with out prior approval of the Justice De partment. The judgment also prohibits Mon santo for a period of 10 years from ac quiring directly or indirectly all or part of any facilities being used in the U.S. in making TDI(80-20) (Mo bay's large-volume product, toluene diisocyanate) or in making flexible urethane foam made from T D I ( 8 0 20), or any capital stock of any cor poration making T D I ( 80-20) or flex ible urethane foam made from TDI(80-20) in the U.S without approval of the Justice Department. The judg ment allows Monsanto to acquire such facilities or stock incidental to an ac quisition made for other purposes provided that Monsanto files an under taking with the court that it will dis pose promptly of such facilities or business. Neither Monsanto nor Bayer dis closes the value of the sale. Although Monsanto won't admit that its sale of its Mobay interests is anything more than a "sound business judgment," it's likely that the company didn't want to face the prospect of a suit that might drag through the courts for years, could be very costly, and might be lost.
PSAC files post-Apollo answer One of the most hotly argued questions in the government space agencies and the aerospace industry is: What comes after Apollo, the manned land ing on the moon? Last week, the President got an answer from his Sci ence Advisory Committee. After a year-long study of the problem, the committee thinks these should be the nation's future space goals: 22 C&EN FEB. 20, 1967
• A limited extension of Apollo to explore the moon. • A strongly upgraded program of exploration of nearby planets aimed at eventual manned expeditions. • Extended operations in nearearth orbit for the advance of science, particularly astronomy. • A development program to qualify man for long-duration space flights. • Extension and vigorous exploita tion of space applications for the social and economic well-being of the nation and for national security. The primary objectives of the U.S. space program in the post-Apollo pe riod should be exploration of the plan ets and space astronomy. This is the opinion of both the President's Science Advisory Committee and the Space Science Board of the National Acad emy of Sciences. These objectives of fer a supreme challenge, PSAC says, because their achievement may bring answers to questions about the origin and evolution of life, of the solar sys tem, and of the universe. Planetary exploration should set the pace for the post-Apollo program. This means that the largest part of the budget for the National Aeronautics and Space Administration should go for programs related to this objective. The promise of eventual manned ex ploration should stimulate the pro gram, PSAC says. However, it is too soon to set up a timetable or pick tar gets. PSAC thinks that for most of the 1970's the program should concen trate on unmanned space probes di rected at Venus, Mars, and Mercury. Meanwhile, NASA should make stud ies to define man's future role in space.
The nation can choose one of sev eral levels of effort. The program can be extremely ambitious and press hard on manned exploration of space or it can be less expensive and emphasize unmanned missions in near-earth space. "But whatever choice of goals may be made," PSAC says, "the pace of the effort must preserve the ele ments of technological and managerial excellence without which the benefits are not realized. At too low a level of effort, the program might lapse into a routine and repetitious series of dem onstrations and collections of data of marginal value." Currently NASA is spending a little more than $5 billion a year on the space effort. To illustrate the relation between program goals and costs, PSAC picked a year at random—fiscal 1972—and worked up budgets for three types of programs (see table). The first program, requiring $3.5 billion, is a marginal-type effort. It has no programs which bear directly on manned explorations. It consists mainly of space astronomy experi ments and unmanned probes. This program could accomplish the bare minimum of results but there is great danger that it does not provide enough challenge to produce important bene fits in developing technological excel lence and stimulating national selfconfidence. The second program, costing $5.8 billion, is the program recommended by the President's Science Advisory Committee. Although there is no sin gle dominating program goal, most of the money is for manned space flight and the large boosters needed.
Urgency of space goals controls spending Fiscal year 1972 alternatives A
C
B (Millions of dollsirs)
Total program
$3500 Per
Lunar exploration Solar system exploration Earth orbital operations Advanced research and technology Launch vehicle support General support
cent
8% 16 19 11 20 26
A—Minimum program; no manned space probes Β—PSAC program; eventual manned explorations C—Expanded program; manned explorations fairly soon Source:
President's Science Advisory Committee
$5800 Per
cent
4% 10 32 10 23 21
$7000 Per
cent
6% 12 33 11 21 17
The third program, costing $7 billion, is a stepped-up version of the PSAC proposal—the second program. One feature of this program would be a specific mission objective; for example, a manned mission to Mars by some fixed date, say 1985. In the committee's opinion, this kind of program is "a vigorous, expanded space program capable of supporting a manned planetary exploration decision at an early date."
Tariff talks not very promising "Unless some agreement is reached within the next two or three weeks in the Kennedy round of tariff negotiations, we've had it.'' That's the word from a top U.S. trade official just back from Geneva, the scene of the bargaining. He still gives the negotiations a 60/40 chance of success but, he admits with a rueful shake of the head, not many are sharing his mildly optimistic view. Authority to negotiate tariffs in the so-called Kennedy round ends June 30 when the Trade Expansion Act of 1962 expires. However, the practical deadline for action is March 31. The reason is that once major agreements have been reached, it will take about three months to work out the details and get the papers signed. The trade official believes that our trading partners are now convinced that the time for foot dragging is over. In the industrial sector, negotiations on chemical tariffs remain at a standstill. The major stumbling block is whether the U.S. will negotiate on the elimination of the American Selling Price system of customs valuation. This system is applied to benzenoid chemicals. U.S. negotiators still maintain this position on ASP: Any conversion of ASP to the normal valuation system would require special counter concessions; Congress would have to approve such a conversion. The U.S. team has not made a firm offer yet but it is considering sacrificing ASP for adjusted tariff rates in return for elimination of nontariff barriers by the European Economic Community. This whole package would be subject to approval by Congress. Tariff negotiations have also bogged down on pulp and paper, aluminum, steel, and farm products. One bright spot is the feeling that an international agreement on how to define and control dumping is likely to emerge from the sessions. Unless negotiations in the Kennedy round reverse themselves and become a success almost overnight, the outlook is grim. Some people think that if the outlook for success is good near the
time when the Trade Expansion Act is due to expire, Congress will automatically extend the act for 30, 60, or 90 days. However, the trade official believes that Congress will not extend the act under any circumstances. There may be strong support for temporary extension in the House, but he believes that the Senate will firmly oppose any such move. If the Kennedy round fails, the trade official thinks that protectionist sentiment in Congress will rise. As a result, the Administration is likely to ask Congress merely for authority to handle routine trade problems.
S atom changes subtilisin A Northwestern University chemist and his Hungarian coworker have shown that changing a single atom in a massive enzyme molecule can drastically change the enzyme's reactivity and produce an essentially new enzyme. They have found that thiolsubtilisin, a modified enzyme made by replacing an oxygen atom in the active site of the native enzyme subtilisin with an atom of sulfur, shows markedly different properties. In their first detailed report on the reactivity of thiol-subtilisin [Biochemistry, 6, 610 (1967)], NU's Dr. Myron L. Bender and coworker Dr. Laszlo Polgar of the Hungarian Academy of Sciences say that the modified enzyme is much less active than subtilisin in most reactions, although it seems to work by the same mechanism in many of them. In some reactions catalyzed by the native enzyme, thiolsubtilisin will not work. But with reactions involving nucleophiles, the modified enzyme is more active. Thiol-subtilisin has also been made by Dr. D. E. Koshland, Jr., and coworkers at the University of California, Berkeley. Dr. Bender explains that hydrolytic reactions catalyzed by enzymes usually work through formation of an intermediate acyl enzyme. The hydroxyl group of a serine residue or the thiol group of a cysteine residue forms an intermediary bond with the substrate. These two residues, which form the active sites of the enzymes, differ in only one atom—the oxygen in the hydroxyl group of the serine or the sulfur atom of the cysteine. This is the change brought about in making thiolsubtilisin from subtilisin. The preparation of thiol-subtilisin takes three steps: • The native enzyme is reacted with phenylmethanesulfonyl fluoride, which completely activates the enzyme. • T h e phenylmethanesulfonyl group is displaced with thiolacetate ion. • The resulting acetyl-thiol-subtilisin
is allowed to deacylate enzymically. Titration with p-chloromercuribenzoate confirms the presence of the thiol group in the product. Amino acid analysis confirms the cysteine residue. Dr. Bender says the synthesis verifies the usefulness of this relatively simple technique for making other enzymes. It can be applied to any enzyme which, like subtilisin, contains no disulfide bridge. Such bridges would be damaged by the thiolacetate. The NU workers find that the catalytic activity of thiol-subtilisin toward p-nitrophenyl acetate and N-trans-cinnamoylimidazole substrates is significantly lower than that of subtilisin. Also, the modified enzyme apparently shows no activity toward alkyl esters and amide substrates such as N-acetylL-tryptophan methyl ester and N-benzoylarginine amide. Dr. Bender says that this inactivity of thiol-subtilisin toward some substrates affected by the native enzyme may be due to an inherently lower activity of the modified enzyme. However, it may be due to a specificity of the modified enzyme for acylating substrates with good leaving groups such as p-nitrophenyl esters and Nfrans-cinnamoylimidazole. In this specificity, thiol-subtilisin would resemble D-glyceraldehyde-3-phosphatedehydrogenase. This generally lower deacylation activity of thiol-subtilisin, compared with subtilisin, is probably due to the larger sulfur atom which presumably changes the steric structure of the active site, Dr. Bender says. This interferes with the substrate-enzyme fit and retards activity. One reaction in which the modified enzyme is more active involves glycinamide. This nucleophile speeds the deacylation of cinnamoyl-thiolsubtilisin but has no effect on cinnamoyl-subtilisin. Dr. Bender says this would be expected as thiol esters in general react more readily with nitrogen nucleophiles than do the corresponding oxygen esters.
Simazine ups plants' protein Scientists at Michigan State's herbicide physiology laboratory have uncovered what may eventually prove to be an aid to solving some of the food problems of the developing, protein-shy areas of the world. In experiments at their laboratory, the MSU scientists have been able to increase the protein content of several food and forage crops by as much as 80% by treating them with trace amounts of simazine, a herbicide used to control weeds around fruit trees. Dr. S. K. Ries, the MSU horticulturist in charge of the simazine research, FEB. 20, 1967 C&EN
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