awk: change whitespaces with tabs taking titles and empty fields into account

I have a space-separated file that I want to turn into a tab-separated file. The file looks like this:

pos    peptide      logscore affinity(nM) Bind Level    Protein Name     Allele
0   GPSGGQPX         0.075        22266                          1 HLA-A11:01
0   PSGGQPXA         0.071        23285                          2 HLA-A11:01
0   SGGQPXAL         0.076        21945                          3 HLA-A11:01
0   GGQPXALD         0.076        21858                          4 HLA-A11:01
0   GQPXALDS         0.075        22237                          5 HLA-A11:01
0   QPXALDSG         0.073        22748                          6 HLA-A11:01
0   PXALDSGY         0.072        22962                          7 HLA-A11:01
0   XALDSGYD         0.080        21133                          8 HLA-A11:01
0   DTSMKDMH         0.093        18194                          9 HLA-A11:01
0   TSMKDMHK         0.732           18         SB              10 HLA-A11:01
0   SMKDMHKV         0.099        17148                         11 HLA-A11:01
0   MKDMHKVL         0.071        23175                         12 HLA-A11:01
0   KDMHKVLR         0.135        11550                         13 HLA-A11:01
0   DMHKVLRT         0.074        22537                         14 HLA-A11:01
0   MHKVLRTL         0.072        23056                         15 HLA-A11:01
0   HKVLRTLQ         0.069        23819                         16 HLA-A11:01
0   DTSMKDMH         0.093        18194                         17 HLA-A11:01
0   TSMKDMHK         0.732           18         SB              18 HLA-A11:01
0   SMKDMHKV         0.099        17148                         19 HLA-A11:01
0   MKDMHKVL         0.071        23175                         20 HLA-A11:01

I have to replace whitespaces with a single tab, taking into account:

1. no tab in "Bind Name" and in "Protein Name" in the title line; they should be renamed "Bind.Level" and "Protein.Name" instead.
2. 2 tabs instead of just 1 (or a "-" or NA in the middle) between the affinity field and the Protein.Name field in those entries where Bind.Level is empty, to preserve such empty entries in that field.

Hence, just the following isn't enough:

 awk '{$1=$1}1' OFS="\t" file

Is there a simple way to accomplish this with a one-liner, preferably awk?

EDIT:

This is how the output should look like, notice "Bind.Level" and "Protein.Name" in the title, and "-" (which can be NA or "") in the empty Bind.Level records

pos peptide logscore    affinity(nM)    Bind.Level  Protein.Name    Allele
0   GPSGGQPX    0.075   22266   -   1   HLA-A11:01
0   PSGGQPXA    0.071   23285   -   2   HLA-A11:01
0   SGGQPXAL    0.076   21945   -   3   HLA-A11:01
0   GGQPXALD    0.076   21858   -   4   HLA-A11:01
0   GQPXALDS    0.075   22237   -   5   HLA-A11:01
0   QPXALDSG    0.073   22748   -   6   HLA-A11:01
0   PXALDSGY    0.072   22962   -   7   HLA-A11:01
0   XALDSGYD    0.080   21133   -   8   HLA-A11:01
0   DTSMKDMH    0.093   18194   -   9   HLA-A11:01
0   TSMKDMHK    0.732   18  SB  10  HLA-A11:01
0   SMKDMHKV    0.099   17148   -   11  HLA-A11:01
0   MKDMHKVL    0.071   23175   -   12  HLA-A11:01
0   KDMHKVLR    0.135   11550   -   13  HLA-A11:01
0   DMHKVLRT    0.074   22537   -   14  HLA-A11:01
0   MHKVLRTL    0.072   23056   -   15  HLA-A11:01
0   HKVLRTLQ    0.069   23819   -   16  HLA-A11:01
0   DTSMKDMH    0.093   18194   -   17  HLA-A11:01
0   TSMKDMHK    0.732   18  SB  18  HLA-A11:01
0   SMKDMHKV    0.099   17148   -   19  HLA-A11:01
0   MKDMHKVL    0.071   23175   -   20  HLA-A11:01

Note that non-empty Bind.Level records might adopt different values, not just "SB"... but all of them alphabetic... Protein.Name might not always be numeric, though...

It would be something like identifying the fields separated by \s+; then, if there are 7 fields, print them as such (separated by tab), and if there are 6 (Bind.Level empty), print $1, $2, $3, $4, "-", $5, $6. Protein.names could potentially contain spaces, but I'm going to make sure it they don't (they are the input). That should be super simple, but I don't know how to do it... anyone??