In article <ckiv7u$i5t$02$1 at news.t-online.com>, Dr Engelbert Buxbaum
<engelbert_buxbaum at hotmail.com> wrote:
>chun.yang at mu.edu wrote:
>>>>> Hi,
>>>> I wonder if the interaction between proteins will be always hydrophobic?
>> Dose anyone can give me an example of hygrophilic interaction between
>> proteins?
>>Ionic and hydrogen bonds involve hydrophilic groups.
I'd be inclined to agree with the point of view that interactions
between proteins are predominantly of hydrophobic nature.
At least, that's certainly is the case of "specific" high affinity
interactions. Sure, hydrogen bonds and a salt bridge here and
there are almost always present and do play a role, occasionally
a crucial one. But hydrophobic interactions of the sort of "surface
complementarity" seem to play a larger role. In fact, this kind
of reasoning is frequently used to distinguish between "biological
interactions" and contacts within crystals. Large contigous areas
of contacts with prominent hydrophobic interactions vs many small
area contacts where primary forces are H-bonds and ionic
interactions in the former and the latter cases, respectively.
I am not an expert but perhaps for precisely this reason I
cannot offhand think of a case where specific high affinity
interaction occurs between highly acidic and highly basic faces of
two proteins. I am sure there are few cases like that but it's
probably more of an exception...
DK
