Gregory Petsko

  Gregory Petsko is a biochemist who studies the proteins of the body and their biochemical function. Working with Dagmar Ringe, he's doing pioneering work in the way we look at proteins and what they do.

  Why you should listen

  Gregory Petsko's own biography, on his Brandeis faculty homepage, might seem intimidatingly abstruse to the non-biochemist -- he studies "the structural basis for efficient enzymic catalysis of proton and hydride transfer; the role of the metal ions in bridged bimetalloenzyme active sites; direct visualization of proteins in action by time-resolved protein crystallography; the evolution of new enzyme activities from old ones; and the biology of the quiescent state in eukaryotic cells."

  But for someone so deeply in touch with the minutest parts of our bodies, Petsko is also a wide-ranging mind, concerned about larger health policy issues. The effect of mass population shifts -- such as our current trend toward a senior-citizen society -- maps onto his world of tiny proteins to create a compeling new worldview.


  Unless we do something to prevent it, over the next 40 years we’re facing an epidemic of neurologic diseases on a global scale. A cheery thought. On this map, every country that’s colored blue has more than 20 percent of its population over the age of 65. This is the world we live in. And this is the world your children will live in.

  For 12,000 years, the distribution of ages in the human populationhas looked like a pyramid, with the oldest on top. It’s already flattening out. By 2050, it’s going to be a column and will start to invert. This is why it’s happening. The average lifespan’s more than doubled since 1840, and it’s increasing currently at the rate of about five hours every day. And this is why that’s not entirely a good thing: because over the age of 65, your risk of getting Alzheimer’sor Parkinson’s disease will increase exponentially. By 2050, there’ll be about 32 million people in the United States over the age of 80, and unless we do something about it, half of them will have Alzheimer’s disease and three million more will have Parkinson’s disease.

  Right now, those and other neurologic diseases -- for which we have no cure or prevention -- cost about a third of a trillion dollars a year. It will be well over a trillion dollars by 2050. Alzheimer’s disease starts when a protein that should be folded up properly misfolds into a kind of demented origami. So one approach we’re taking is to try to design drugs that function like molecular Scotch tape, to hold the protein into its proper shape. That would keep it from forming the tangles that seem to kill large sections of the brain when they do. Interestingly enough, other neurologic diseases which affect very different parts of the brain also show tangles of misfolded protein, which suggests that the approach might be a general one, and might be used to cure many neurologic diseases, not just Alzheimer’s disease.

  There’s also a fascinating connection to cancer here, because people with neurologic diseases have a very low incidence of most cancers. And this is a connection that most people aren’t pursuing right now, but which we’re fascinated by. Most of the important and all of the creative work in this area is being funded by private philanthropies. And there’s tremendous scope for additional private help here, because the government has dropped the ball on much of this, I’m afraid. In the meantime, while we’re waiting for all these things to happen, here’s what you can do for yourself. If you want to lower your risk of Parkinson’s disease, caffeine is protective to some extent; nobody knows why. Head injuries are bad for you. They lead to Parkinson’s disease. And the Avian Flu is also not a good idea. As far as protecting yourself against Alzheimer’s disease, well, it turns out that fish oil has the effect of reducing your risk for Alzheimer’s disease.

  You should also keep your blood pressure down, because chronic high blood pressure is the biggest single risk factor for Alzheimer’s disease. It’s also the biggest risk factor for glaucoma, which is just Alzheimer’s disease of the eye. And of course, when it comes to cognitive effects, "use it or lose it" applies, so you want to stay mentally stimulated. But hey, you’re listening to me. So you’ve got that covered. And one final thing. Wish people like me luck, okay? Because the clock is ticking for all of us. Thank you.


  如果我们还不采取措施开始保护的话 那么40年后,我们将面临一场 神经疾病的全球性蔓延。 比较有意思的想法哈。 在这张地图上,所有蓝色区域的国家中 百分之20的人口年龄大于65岁。 这是现在的情况。 这是我们下一代的情况。 12000年前,人口年龄分布图 像一座金字塔,年长者在顶端。 现在,顶端基本上已经平坦了。 预计到2050年时,整个分布图会变成柱状并开始上下颠倒。

  发生这种变化的原因是。 人类的平均寿命长度已经从1840年时翻了一倍 并且还在以每天5小时的速度增加 这并不全是一个好消息,因为: 当人们65岁以后,患老年痴呆症 和帕金斯症的机率会成指数级增加 到2050年时,美国会有3千2百万人 年龄大于80岁,如果我们还不采取措施的话 他们中的一半会得老年痴呆症 三百万人会得帕金斯症。 当前,这类神经疾病 我们还无法治愈或预防 尽管我们每年要花费掉将近3000亿美元 这个数字到2050年预计会超过1万亿美元。

  老年痴呆症的发生就像是 本来应该折叠成正确形状的蛋白质 被胡乱揉成一团 因此我们可以设想:能否制造 一种分子胶 把蛋白质固定成它本来的形状 这样就可以避免在它变形的过程中缠结一团 从而破坏了大面积的脑神经 更有意思的是:在其他一些 影响不同脑功能的神经类疾病 ,也发现了错误折叠纠缠一团的蛋白质 这就是说:原因也许是一致的 也许可以用来治疗很多神经类疾病 并不只是老年痴呆症 另外,神经疾病还与癌症有密切关系。 因为神经疾病患者的 各种癌症的发病率都很低 绝大多数人都还没有去探索这两者之间的关系 但我们对此却很感兴趣。 最重要的一点是:所有该领域的有创造性的研究资金全部 来自于私人慈善贡献。 该领域还需要巨大的私人资金支持因为恐怕政府不太关注这个领域。

  同时,在等待过程中, 可以为自己做些预防 如果你想减少患帕金森症的机率 咖啡因似乎有些作用,但没人知道为什么。 头部受伤会增加患帕金斯症的机率。 禽流感也一样。 至于预防老年痴呆症 鱼油是可以有效地 降低患老年痴呆症的风险。 另外,还应该注意保持血压 因为慢性高血压 是最有可能导致老年痴呆症的。 同时也是最有可能导致青光眼的 青光眼其实就是“老年痴呆症-眼睛版” 当然涉及到认知的影响时 “用进废退”原则适用 所以如果想要保持精神刺激的话 那么你们听见我说的了吧。 那样这部分就没问题啦。 最后,祝愿像我这样的科研人员幸运。 因为时钟滴答作响,时不我待。 谢谢