Hydrolases

[Poison]

OK here is a question about hydrolases. someone tried to explain it to me but, I don't think I totally understood.
Enzymes are proteins, which means has peptide bonds. ( I think we all agree about that.) Think about an active hydrolase which breaks down peptide bonds. While the enzyme is doing its job, how come it doesn't break down its own bonds together with others?
Hope someone can explain this to me.

PS: You can call me stupid, but I could't find a solution.

[loupass]

The way the amino acids are put together in the protein will determine the 3-dimensional structure of the protein. Hydrolases are enzymes and all enzymes recognize a specific sequence much like a lock recognizes a key. Enzymes will recognize a target protein by various means including its three dimensional structure. Hence, an enzyme (which is a protein) will recognize a specific recognition sequence or conformation but it will not contain that sequence or conformation itself. Thus it cannot degrade itself.

[MrMistery]

Perfect explanantion, except:

all enzymes recognize a specific sequence much like a lock recognizes a key.

It's the other way around i think: like a key recognises a lock

[mith]

Lol, like a 12 year old recognizing a 9 year old

[loupass]

key-lock, lock-key makes no real difference, the analogy is there. I just think of the enzyme as the lock. Glad you liked the explanation.

[Poison]

Guys, the key-lock cannot be the answer. Because, an enzyme molecule would break down the others bond according to your explanation. Key- lock means, the enzyme's active site is getting together with the substrate. The active site of one enzyme molecule would get together with another enzyme molecule. But it doesn't. And how can this be possible.
I tried to explain the one who asked me this question (actually he knows the answer, but he doesn't tell.) with the active site and key lock stuff. And he explained it to me (as i did above) that it is not the point.

[cytochromeP]

The active site of one enzyme molecule would get together with another enzyme molecule. But it doesn't. And how can this be possible.
I tried to explain the one who asked me this question (actually he knows the answer, but he doesn't tell.) with the active site and key lock stuff. And he explained it to me (as i did above) that it is not the point.

Well I believe the answer lies in Natural Selection. It can be explained as below:
1) A hydrolase which binds other hydrolase molecules of its type may have gotten eliminated thru natural selection if it did not impart any evolutionary advantage to the organism.
OR
2) We will have to wait longer till the evolutionary process gives rise to such a self-hydrolysing hydrolase in question.

[Poison]

BUt if you think logically, peptide bonds are all the same. A hydrolase which breaks down peptide bonds would break down its bonds as well. It didn't seem logical enough to me. I mean I'm not wondering if or not there is an hydrolase does that because it doesn't. I wonder WHY?

[canalon]

See http://encyclopedia.thefreedictionary.com/Peptidase
they state that:"As peptidases are themselves peptides, one natually wonders if they degrade themselves. In fact, many peptidases are known to cleave themselves or each other. This may be an important method of regulation of peptidase activity."

Self hydrolysis do indeed happen !

Patrick

[MrMistery]

I think that is the one posibility that none of us thought of

[Poison]

Thank you VERY much!!!! I was trying to find an answer for over 3 months!!! I think the person who asked this question was trying to make me confused. And he succeeded.

[Jelanen]

Just to add....
An enzyme active site is not some uninteresting 2-D touch pad and when the sustrate hits it, the enzyme works. An active site is a complex (very) 3-D site that not only involves the physical shape of the sustrate(s), but also their size, precise orientation of their electrochemical patterns, and pH. The anology of scissors is useful for understanding what hydrolytic enzymes do, but are woefully inadequate in the actual look and mechanism departments.

-Jelanen