3 ms·

Slightly misleading headline, as PET (polyethylene terephthalate) hydrolases were already known - see https://www.chm.bris.ac.uk/motm/PETase/PETaseh.htm https:/

Slightly misleading headline, as PET (polyethylene terephthalate) hydrolases were already known - see https://www.chm.bris.ac.uk/motm/PETase/PETaseh.htm https://www.chm.bris.ac.uk/motm/PETase/PETaseh.htm This is a study of an archaeal enzyme (from the deep-sea) that can degrade both long-chain and short-chain polymers that is more efficient at 70 deg C than other enzymes. The details are that this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site. The authors suggest this lid domain replaces the conserved Trp that is an Ala in the archaeal enzyme.

pneumic 3y ago
Yeah, it's not bad news at all but it appears to be one of many that still require considerable heat, industrial infra, etc. Has anyone attempted to put these enzymes to the test in at some scale in an industrial setting, I wonder?
- hanniabu 3y ago
  Should work well in landfills since there's heat buildup
- gilleain 3y ago
  No idea. From skimming some university press releases, I see a lot of "potential for!" and similar wording. This https://news.utexas.edu/2022/04/27/plastic-eating-enzyme-could-eliminate-billions-of-tons-of-landfill-waste/ https://news.utexas.edu/2022/04/27/plastic-eating-enzyme-cou... has "Up next, the team plans to work on scaling up enzyme production to prepare for industrial and environmental application. " which is more promising. As far as I understand, yes it is a very different challenge to make a bioreactor for actually using some random new enzyme than the (also hard) problem of getting the structure in the first place. How to immobilize it on some surface, how to pre-process the material to pass it through the reactor (?) I guess ...
  - justaskme 3y ago
    Feels like it's always "potential for"... sigh
- jamesjuicy55 3y ago
  https://www.purecycle.com/who-we-are https://www.purecycle.com/who-we-are. ?
- hinkley 3y ago
  I mean my processor hits 70° and has for a decade or more, and my car engine thinks 87° is the happy temperature. 70° is maybe a little out of the reach of a home system but nothing for a municipal system. Right?
  - kardos 3y ago
    A hot water tank is not far from 70C
- eindiran 3y ago
  I was recently at a party and spent some time talking with someone who has a stealth startup working on this exact problem. He said that they aren't the first, but getting the scale right (in an industrial setting) and finances right enough that someone is willing to spend the money to set it up is far harder than just finding an enzyme that can break down PET / similar polymers.
hanniabu 3y ago
> Slightly misleading headline, as PET (polyethylene terephthalate) hydrolases were already known It doesn't say it was the only one, just a newly discovered one
- gilleain 3y ago
  Sure, fair enough. I just thought people might read it as "Enzyme with new ability (to break down PET) discovered", but maybe I was being pessimistic.
  - capableweb 3y ago
    It's also mentioned in the article body: > Until now, about 80 different PET-degrading enzymes were known, most of which were found in bacteria or fungi.
    - digging 3y ago
      Most of us aren't reading the body though.
testfoobar 3y ago
"this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site" As educated as I think I am, it is always humbling to read a hacker news comment that I cannot understand. ELI5?
- gilleain 3y ago
  Apologies, that was meant for the specialists :) It is mostly just technical jargon so do not feel too humble ... So I'll break it down: - "feruloyl esterase" : an 'esterase' is an enzyme that makes or breaks ester bonds. In this case, 'feruloyl' which I've never heard of but apparently is some small molecule that is normally attached to a sugar. https://en.wikipedia.org/wiki/Feruloyl_esterase https://en.wikipedia.org/wiki/Feruloyl_esterase - "conserved alpha/beta-hydrolase fold" : a structural pattern (fold) that is shared (conserved) between a set of structures. In other words, these enzymes all have roughly the same shape. https://www.cathdb.info/version/v4_3_0/superfamily/3.40.50.1820 https://www.cathdb.info/version/v4_3_0/superfamily/3.40.50.1... - "additional flexible 'lid' domain that covers the active site" : a 'domain' is just a compact part of a protein, without going into too much detail. They are calling it a 'flexible lid' as the idea is that it moves out of the way to bind the substrate to the active site (where the reaction is carried out) and back again when fully bound.
  - testfoobar 3y ago
    Thank you.
    - andresgottlieb 3y ago
      I've been using ChatGPT4 for this situtations, with excellent results. Check out this conversation about it (I used a PDF reader plugin, also): https://chat.openai.com/share/a682c5a7-f2c5-4849-a999-5a7218d17877 https://chat.openai.com/share/a682c5a7-f2c5-4849-a999-5a7218...
- neftaly 3y ago
  Enzymes are kind of like a tool for breaking apart lego blocks, or a jig for assembling them. This sounds like a moving part that covers the "teeth" and makes it more effective (or less likely to get jammed by the wrong molecules?).

pneumic 3y ago

Yeah, it's not bad news at all but it appears to be one of many that still require considerable heat, industrial infra, etc. Has anyone attempted to put these enzymes to the test in at some scale in an industrial setting, I wonder?

hanniabu 3y ago
Should work well in landfills since there's heat buildup
gilleain 3y ago
No idea. From skimming some university press releases, I see a lot of "potential for!" and similar wording. This https://news.utexas.edu/2022/04/27/plastic-eating-enzyme-could-eliminate-billions-of-tons-of-landfill-waste/ https://news.utexas.edu/2022/04/27/plastic-eating-enzyme-cou... has "Up next, the team plans to work on scaling up enzyme production to prepare for industrial and environmental application. " which is more promising. As far as I understand, yes it is a very different challenge to make a bioreactor for actually using some random new enzyme than the (also hard) problem of getting the structure in the first place. How to immobilize it on some surface, how to pre-process the material to pass it through the reactor (?) I guess ...
- justaskme 3y ago
  Feels like it's always "potential for"... sigh
jamesjuicy55 3y ago
https://www.purecycle.com/who-we-are https://www.purecycle.com/who-we-are. ?
hinkley 3y ago
I mean my processor hits 70° and has for a decade or more, and my car engine thinks 87° is the happy temperature. 70° is maybe a little out of the reach of a home system but nothing for a municipal system. Right?
- kardos 3y ago
  A hot water tank is not far from 70C
eindiran 3y ago
I was recently at a party and spent some time talking with someone who has a stealth startup working on this exact problem. He said that they aren't the first, but getting the scale right (in an industrial setting) and finances right enough that someone is willing to spend the money to set it up is far harder than just finding an enzyme that can break down PET / similar polymers.

hanniabu 3y ago

> Slightly misleading headline, as PET (polyethylene terephthalate) hydrolases were already known It doesn't say it was the only one, just a newly discovered one

gilleain 3y ago
Sure, fair enough. I just thought people might read it as "Enzyme with new ability (to break down PET) discovered", but maybe I was being pessimistic.
- capableweb 3y ago
  It's also mentioned in the article body: > Until now, about 80 different PET-degrading enzymes were known, most of which were found in bacteria or fungi.
  - digging 3y ago
    Most of us aren't reading the body though.

testfoobar 3y ago

"this is a feruloyl esterase with a conserved alpha/beta-hydrolase fold but with an additional flexible 'lid' domain that covers the active site" As educated as I think I am, it is always humbling to read a hacker news comment that I cannot understand. ELI5?

gilleain 3y ago
Apologies, that was meant for the specialists :) It is mostly just technical jargon so do not feel too humble ... So I'll break it down: - "feruloyl esterase" : an 'esterase' is an enzyme that makes or breaks ester bonds. In this case, 'feruloyl' which I've never heard of but apparently is some small molecule that is normally attached to a sugar. https://en.wikipedia.org/wiki/Feruloyl_esterase https://en.wikipedia.org/wiki/Feruloyl_esterase - "conserved alpha/beta-hydrolase fold" : a structural pattern (fold) that is shared (conserved) between a set of structures. In other words, these enzymes all have roughly the same shape. https://www.cathdb.info/version/v4_3_0/superfamily/3.40.50.1820 https://www.cathdb.info/version/v4_3_0/superfamily/3.40.50.1... - "additional flexible 'lid' domain that covers the active site" : a 'domain' is just a compact part of a protein, without going into too much detail. They are calling it a 'flexible lid' as the idea is that it moves out of the way to bind the substrate to the active site (where the reaction is carried out) and back again when fully bound.
- testfoobar 3y ago
  Thank you.
  - andresgottlieb 3y ago
    I've been using ChatGPT4 for this situtations, with excellent results. Check out this conversation about it (I used a PDF reader plugin, also): https://chat.openai.com/share/a682c5a7-f2c5-4849-a999-5a7218d17877 https://chat.openai.com/share/a682c5a7-f2c5-4849-a999-5a7218...
neftaly 3y ago
Enzymes are kind of like a tool for breaking apart lego blocks, or a jig for assembling them. This sounds like a moving part that covers the "teeth" and makes it more effective (or less likely to get jammed by the wrong molecules?).