Word: proteins
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Dates: during 1960-1969
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...sensitized, so that his next shot may produce a severe reaction marked by rash, fever, swollen glands and pain in the joints. In a few cases, the response is so fast and catastrophic that it is called anaphylactic shock, a violent reaction usually associated with the introduction of foreign protein into the system. A patient thus afflicted may die within minutes...
Since penicillin molecules are not proteins, he reasoned, they must somehow get hooked up to a protein. Sure enough, when he had basic penicillin preparations put through careful laboratory separation procedures, two fractions appeared: a pure penicillin that did not cause reactions in sensitized guinea pigs and a minute quantity of a second substance that produced violent reactions. This second substance proved to be a large protein molecule, with part of the penicillin molecule attached. The protein can be removed in the final stages of manufacture, thus making injected penicillin much safer for the non-sensitized patient...
Other purification procedures yielded a second impurity. Not a protein, it appears to be a product of the penicillin molecule itself, which forms spontaneously after penicillin is stored for even a short time. As its formation cannot be completely prevented, penicillin injections for patients known to be sensitive are still too risky...
...findings reported in the Lancet by three research groups go far to ex plain another mystery of penicillin -why it is so much less likely to cause severe reactions when taken by mouth than when injected. It seems that much of the protein impurity is destroyed - digested, in effect - in the alimentary tract before it can get into the bloodstream...
...Massachusetts Institute of Technology, thought there must be something on the ends of the basic molecules that enabled them to couple. Dr. Albert L. Rubin and an M.I.T. team set about testing the theory. They found that each collagen strand has a tail or tails consisting of smaller protein molecules that determine the linkages. Cut off the tails, and what remains is short strands of colla gen that can be recombined in almost any desired "weave," shape or thickness, and with varying degrees of softness or hardness. More important, when the tails are cut off, the collagen molecules lose most...