code: @Override
  	public void toPDB(StringBuffer buf){
  
  		/*12 - 14        LString(3)      "CYS"        Residue name.
  		16             Character       chainID1     Chain identifier.
  		18 - 21        Integer         seqNum1      Residue sequence number.
  		22             AChar           icode1       Insertion code.
  		26 - 28        LString(3)      "CYS"        Residue name.
  		30             Character       chainID2     Chain identifier.
  		32 - 35        Integer         seqNum2      Residue sequence number.
  		36             AChar           icode2       Insertion code.
  		60 - 65        SymOP           sym1         Symmetry oper for 1st resid
  		67 - 72        SymOP           sym2         Symmetry oper for 2nd resid
  		*/
  		//01234567890123456789012345678901234567890123456789012345678901234567890123456789
  		//SSBOND   1 CYS      5    CYS     55                                     5PTI  67
  		//SSBOND   2 CYS     14    CYS     38
  		//SSBOND   3 CYS     30    CYS     51
  
  
  		buf.append("SSBOND ");
  		buf.append(String.format("%3d", serNum));
  		buf.append(String.format(" CYS %s %4s%1s  ", chainID1, resnum1, insCode1));
  		buf.append(String.format(" CYS %s %4s%1s  ", chainID2, resnum2, insCode2));
  
  	}
docs: Append the PDB representation of this SSBOND to the provided StringBuffer
  
  @param buf a StringBuffer to print the PDB representation to